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Search Results: 1 - 10 of 3846 matches for " 霍云云 "
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基于三维激光扫描仪的坡面细沟侵蚀动态过程研究
云云,吴淑芳,冯浩,原立峰
中国水土保持科学 , 2011,
Abstract: ?利用三维激光扫描仪探索多场降雨情况下同一坡面细沟侵蚀的动态过程,为解释细沟侵蚀过程提供一定的理论依据。采用室内人工模拟降雨,在坡度为15°的土槽上进行恒降雨强度的7场降雨冲刷实验,利用三维激光扫描仪对每场降雨冲刷后的坡面形态进行了监测,定量分析坡面细沟侵蚀的动态发育过程。结果表明:前2场降雨与后5场降雨产流产沙过程和细沟侵蚀发育过程有较大差异,细沟从第3场降雨开始明显发育。表现为小跌水一下切沟头一断续细沟一连续细沟一细沟沟网的发育过程。通过三维激光扫描仪精确监测7场降雨坡面各点微地形变化,发现细沟平均沟宽、平均沟深、沟长最大值、细沟平均密度在前2场降雨增长幅度较小,至第3场降雨后开始迅速增人,细沟侵蚀强度不断加强。侵蚀强度由第1场降雨的0.103kg/m2发展至第7场降雨的8.788kg/m2,增加了84倍。
元胞大小选择对坡面细沟侵蚀过程ca模拟的影响
原立峰,刘星飞,吴淑芳,云云
武汉大学学报(信息科学版) , 2014,
Abstract: ?目的在已建立的黄土坡面细沟侵蚀ca模型基础上,侧重研究不同元胞大小对坡面细沟发育过程和细沟特征参数的影响。通过累积径流量和累积侵蚀量的nash-sutcliffe系数ens和误差系数re,分析元胞大小对ca模型有效性的影响。当保持模型其他参数和运行时间都不变时,元胞尺寸增大,细沟发育过程加速,细沟平均沟宽变宽,沟长变长,坡面径流和产沙的趋势提前,同时累积径流量减小,累积侵蚀量增加;当元胞尺寸变小时则相反。由于ca模型的流速是由元胞边长和时间步长的比值来决定的,所以只有其与实验坡面流速接近时才能提高模型的有效性。
不同空间尺度下的土壤侵蚀元胞自动机建模评述
刘星飞,原立峰,吴淑芳,云云
中国水土保持科学 , 2012,
Abstract: ?土壤侵蚀系统是一个典型的非线性动力系统,系统内部的侵蚀发育演化过程十分复杂,为了对该过程进行精确的模拟和预测,需要发展有效的技术和方法。元胞自动机(cellularautomata,ca)是一种具有时空特征的离散动力学模型,采用“自下而上”的构模方式,对于模拟和分析具有空间特征的土壤侵蚀系统具有先天优势。由于空间尺度变化所引起的土壤侵蚀因子对侵蚀产沙过程的影响不同,ca模型在坡面尺度下主要针对细沟侵蚀和土壤颗粒的变化,在小流域尺度下涉及到更多的元胞状态和更加完整的侵蚀过程,在大区域尺度下重点研究气候和地貌之间的相互作用。不同空间尺度建立的ca模型没有确定的转换规则,模型通用性较低,今后需要在三维可视化、智能化等方面深入研究ca模型在土壤侵蚀领域的应用。
Dynamic process of slope rill erosion based on three-dimensional laser scanner
基于三维激光扫描仪的坡面细沟侵蚀动态过程研究

Huo Yunyun,Wu Shufang,Feng Hao,Yuan Lifeng,
云云
,吴淑芳,冯浩,原立峰

中国水土保持科学 , 2011,
Abstract: In this paper,the 3D laser scanner were used to probe the dynamic process of rill erosion under the same slope by a multi-rainfall condition,which may provide certain theoretical basis for explaining the rill erosion process.The artificial rainfall simulation in room were adopted.Seven rainfall scouring experiments with the constant rainfall intensity were carried out on the soil bin with the slope of 15° and the 3D laser scanner was used to make the real-time monitoring of the slope pattern after each rainfall.The studies mainly focus on the dynamic development process of slope rill erosion.Results showed that there were great differences in the process of runoff,sediment and the development of rill erosion.Between the first two rainfall events and the last five ones.The rill developed obviously after the third rainfall event.Rill erosion process was presented as: small hydraulic drop-incised gully head-intermittent rill-continuous rill-rill network.By monitoring the changes of the slope points in microtopography using 3D laser scanner,it was found that the change range of landform is relatively small in the average rill width,the average rill depth,the maximum rill length,the average rill density during the first two rainfall events.These parameters began to increase rapidly after the third rainfall event.Rill erosion intensity was constantly strengthened from 0.103kg/m2 under the first rainfall to 8.788kg/m2 under the seventh rainfall with an increase of 84 times.
基于变分水平集方法的散乱数据曲面重构研究
Surface Reconstruction from Scattered Data Based on Variational Level Set Method
 [PDF]

云云, 朱华平
Journal of Image and Signal Processing (JISP) , 2016, DOI: 10.12677/JISP.2016.52007
Abstract:
工程学和医学等领域中的很多问题进行抽象后可转化为散乱数据的光滑曲面重构问题。在散乱数据附近设定初始轮廓,将初始轮廓间接地表示为水平集函数的零水平集形式,最终将初始活动轮廓的演化转化成水平集函数的演化。定义一个以水平集函数为自变量的能量泛函来度量它与散乱点的逼近程度,利用改进的变分水平集方法演化初始轮廓,达到重构目的。本文中,一是对Heaviside函数进行改进,使初始轮廓能更好的收敛于目标轮廓;二是给出了模型数值计算的具体过程,并以二维实例说明散乱数据重构的效果。
A lot of problems in the field of engineering and medicine after abstraction can be converted into scattered data reconfiguration problems. We set initial contour near the scattered data, expressed as the zero level set of the level set function, which will eventually turn the evolution of initial active contour into the evolution of the level set function. We define an energy functional who takes the level set function as its independent variable, to measure approximation degree with the scattered data, and use the improved variational level set method to evolve the initial contour and achieve reconstruction. In this paper, firstly, putting forward an improved Heaviside function to make the initial contour can better converge in the target contour; secondly, the specific process of numerical calculation model is given, and a two-dimensional example illustrates the effect of the scattered data reconstruction.
基于动量BP算法的多元χ控制图的识别研究
云云
福州大学学报(自然科学版) , 2010,
Abstract: 采用增加动量项的权值调整公式, 运用3层的BP神经网络对χ控制图的失控信号进行识别, 诊断失控的质量特性, 并判断均值偏移的程度类别, 及时调整过程于稳定状态. 实例结果表明, BP网络结合χ控制图能有效地对过程进行监控.
北宋礼学的转向 ――以濮议为中心
云云
安徽大学学报(哲学社会科学版) , 2010,
Abstract: 濮议是融礼仪、礼制、礼意、礼经为一体的礼学争议问题。从思想史角度考察其意义,可以获悉北宋儒学思想发展的新动向。司马光等人从维护皇权专制统治出发,强调“礼”具有的社会规范价值,以及对于维持尊卑等级结构的现实意义。欧阳修等人则从“礼”赖以存在的基础着手,彰显“礼”的人性本质,突出“礼”的内在精神实质与外在表现形式的相依关系。程颐从宇宙自然秩序入手,提出“天理”是“礼”的根本所在,坚守“礼”的伦常本位,对礼学融入理学的历史转变具有重要意义。
蓝细菌钙化作用
,云云
- , 2017,
Abstract: 蓝细菌钙化作用,是一种主要通过光合作用吸收CO2 和 HCO-3并产生鞘内的pH值变化来实现诱导碳酸盐矿物沉淀的重要机制。蓝细菌钙化产物是那些谜一样的化石,如葛万菌、附枝菌、肾形菌。钙化蓝细菌化石的地史分布表明,蓝细菌钙化作用与海水化学条件及大气圈CO2和O2含量的长时间变化存在着成因联系,从而成为重要的生物沉积现象。多年的研究表明,当p(CO2)分压下降到10 PAL(present atomosphere level)以下及p(O2)分压上升时,诱导了蓝细菌鞘内二氧化碳浓缩机制(CCMs)的形成。CCMs促进的活体内鞘的钙化作用,与大气圈的CO2浓度有着直接的生态生理学联系。在1.2 Ga最早的活体内钙化蓝细菌鞘可能反映了CCMs相对早期的起源。追逐蓝细菌钙化作用,不但拓宽了沉积学的研究范畴,也为了解那些谜一样的钙化化石的生物亲和性提供一些新的理念和思考途径。
寒武系凝块石生物丘的沉积组构:以鲁西地区张夏组为例
Sedimentary Fabrics for the Cambrian Thrombolite Bioherm: An Example from the Zhangxia Formation in Western Shandong Province

云云
- , 2016,
Abstract: 摘要: 凝块石是一种不具纹层状组构的微生物碳酸盐岩,与纹层状组构的叠层石形成鲜明对照。鲁西地区寒武系张夏组中的凝块石生物丘主要由致密泥晶和微亮晶组成的团块构成,在团块中可见到细胞外聚合物质(EPS)钙化作用的残余物及钙化蓝细菌化石。在复杂的微观组构中,表现出球状结构、片状、席状及蜂窝状结构的EPS钙化残余物,说明凝块石中团块的形成是一个复杂的有机矿化作用过程。这些EPS钙化残余物与较为普遍的致密泥晶和钙化蓝细菌化石一起,为了解凝块石的形成机理提供了一些重要信息。因此,对凝块石生物丘的分析也为今后的深入研究提供了一个重要线索和思考途径。
Abstract: Thrombolite is a non-laminated fabric of microbial carbonate, which is in a sharp contrast with stromatolite that is characterized by the laminated fabric. Thrombolite bioherm developed in Cambrian Zhangxia Formation in the western Shandong Province mainly consists of clots, which are composed of dense micrite and microspar. Both the remain of calcified extracelluar ploymers (EPS) and calcified cyanobacteria fossils are observed within the clots that make up thrombolite. Within the complex microscopic fabrics it can be observed that the remain of calcified EPS is marked by the spherical structure, the sheet structure, the mat structure and the honeycomb-like structure, and it further indicates that the formation of clots within thrombolite should belong to a complex organic mineralization process. Together with both the dense micrite and the calcified cyanobcteria fossil, the calcified EPS provide some important information for understanding the enigmatic formation mechanism of thrombolites. Therefore, the study of Cambrian thrombolite bioherm can provide an important clue and approach for the further research
珠江三角洲都市圈国内旅游者空间行为模式研究
陆林,云云
地理科学 , 2014,
Abstract: 以珠江三角洲(下称珠三角)都市圈国内主要客源地2009~2011年度中国100强旅行社官网旅游线路报价单为基础数据,研究了珠三角都市圈发展较为成熟阶段的旅游者空间行为模式及目的地类型,发现①珠三角都市圈旅游者空间行为模式总体上以营区基地式和完全环游式为主。不同客源地旅游者行为模式差异较大,广东省内旅游者以单目的地式和港澳小环游为主,其余客源地旅游者多采用营区基地式、往返式、区域环游式和完全环游式等旅行模式;②珠三角都市圈各城市在旅游线路中出现的频次存在较大差异,总体呈现出3个等级层次关系,不同城市在大小珠三角都市圈以及不同客源地旅游线路中的角色与地位不同,据此得出珠三角都市圈各客源地的空间行为模式图;③比较大小珠三角都市圈在空间行为模式上的差异,发现港澳与珠三角地区在旅游发展上逐渐成为一个联系紧密的整体,但实现三地旅游一体化尚待时日。
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