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用插值细分表面模拟方法辅助生成表面有限元网格的研究 被引量:1
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作者 邓志平 王宇 《中国机械工程》 EI CAS CSCD 北大核心 2009年第16期1951-1955,共5页
将表面插值技术和传统的Delaunay三角单元生成技术结合在一起,设计出一种新的生成表面网格的方案。使用该方案可以避免非连续表面模拟中传统解析模型的缺点,并能非常容易地在离散测量值的基础上建立起辅助几何表面模型,应用结果表明,该... 将表面插值技术和传统的Delaunay三角单元生成技术结合在一起,设计出一种新的生成表面网格的方案。使用该方案可以避免非连续表面模拟中传统解析模型的缺点,并能非常容易地在离散测量值的基础上建立起辅助几何表面模型,应用结果表明,该方案工作良好,能很好地控制网格的尺寸和分布,生成的单元具有较好的形状,同时能够很好地处理表面上的突变和尖角。该方案的这些特性使其在环境科学和工程领域的有限元计算中拥有了非常大的应用潜力。 展开更多
关键词 有限元 表面网格生成 插值细分表面模拟方法 Delaunay三角单元生成法
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细分表面处理函数初探
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作者 惠晓钟 《陕西国防工业职业技术学院学报》 2006年第2期29-32,共4页
本文分析了3DSMAX中常用的细分表面处理函数。这些函数包括以下功能:当前项点的锐化特性、用指定名称定义细分表面、为当前表面定义皱褶边、改变细分表面默认的近似表面、为当前表面定义一条修建边等。本文分析了这些函数的常用参数,阐... 本文分析了3DSMAX中常用的细分表面处理函数。这些函数包括以下功能:当前项点的锐化特性、用指定名称定义细分表面、为当前表面定义皱褶边、改变细分表面默认的近似表面、为当前表面定义一条修建边等。本文分析了这些函数的常用参数,阐述了各个函数的应用方法,对那些三维建模编程工作者有所帮助。 展开更多
关键词 三维建模 三维软件编程 细分表面 3DS MAX
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物体表面细分近似最优方法的分析
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作者 王飞戈 程学军 《微计算机信息》 2009年第30期199-201,共3页
基于模型上采集的非组织的样本点数据,我们给出了表面细分的一个框架。通过研究和分析几何上近似最优的表面细分的方法:平方距离最小,来揭示它的相交性与稳定性,以及非线性约束的最优化问题。从而保证了表面细分稳定的相交,并实现了最... 基于模型上采集的非组织的样本点数据,我们给出了表面细分的一个框架。通过研究和分析几何上近似最优的表面细分的方法:平方距离最小,来揭示它的相交性与稳定性,以及非线性约束的最优化问题。从而保证了表面细分稳定的相交,并实现了最优方法的近似。 展开更多
关键词 分析 细分表面 最优化
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表面细分的最优方法的分析与设计
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作者 杨勇 顾耀林 《计算机工程与应用》 CSCD 北大核心 2009年第17期174-177,220,共5页
基于模型上采集的非组织的样本点数据,给出了一个非线性至少平方的表面细分的完整框架。通过研究和分析三个几何上最优的表面细分的方法:点距离最小、切线距离最小、平方距离最小,来揭示它们的相交性与稳定性,以及非线性约束最优化的内... 基于模型上采集的非组织的样本点数据,给出了一个非线性至少平方的表面细分的完整框架。通过研究和分析三个几何上最优的表面细分的方法:点距离最小、切线距离最小、平方距离最小,来揭示它们的相交性与稳定性,以及非线性约束最优化的内部联系。对于点距离最小方法的分析,它是切线下降的变体,因此,只有线性相交。对于切线距离最小方法,它是接近二次相交零余留的问题,也有可能没有相交。平方距离最小方法,可以通过牛顿公式得到,并且是三种方法中相对最优的。通过对这三种方法的研究,来保证表面细分稳定地相交,且解决了对最优方法的争议。 展开更多
关键词 分析 设计 细分表面 最优化
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表面细分技术在二维声辐射和声散射中的应用 被引量:3
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作者 文立华 王卫祥 张敏玉 《应用声学》 CSCD 北大核心 2006年第1期13-18,共6页
把表面细分技术应用于求解边界积分方程,既能把CAD模型直接用于边界元分析,又能精确描述复杂的边界几何形状,实现网格自动加密和形函数自动升阶,满足误差要求。把它应用于简单的二维声辐射和声散射,结果表明对提高边界元方法的计算精度... 把表面细分技术应用于求解边界积分方程,既能把CAD模型直接用于边界元分析,又能精确描述复杂的边界几何形状,实现网格自动加密和形函数自动升阶,满足误差要求。把它应用于简单的二维声辐射和声散射,结果表明对提高边界元方法的计算精度是有效的。 展开更多
关键词 表面细分 细分矩阵 边界积分方程 声辐射 声散射
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表面细分理论的研究 被引量:2
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作者 涂超 《广东工业大学学报》 CAS 2002年第1期26-31,共6页
表面细分技术是一种实现可伸缩几何的重要方法。为了能适应不同性能的硬件平台 ,该技术能有效地控制渲染时模型中多边形数量 ,对于提高三维应用系统的实时性能具有十分重大的意义 表面细分就是一种利用多边形模型来描述一个表面的方法
关键词 可伸缩几何 表面细分 虚拟现实 多边形模型 渐进模型 控制网 地理信息系统
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基于表面细分技术的边界谱方法
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作者 文立华 王卫祥 《西北工业大学学报》 EI CAS CSCD 北大核心 2005年第6期720-724,共5页
把表面细分技术与边界谱方法相结合,提出了一种基于表面细分技术的子波边界谱方法。它能精确描述复杂图形边界,提高处理复杂边界问题的能力和计算精度,把表面细分技术建立的几何模型直接用于边界谱方法的求解。数值算例表明,该方法是有... 把表面细分技术与边界谱方法相结合,提出了一种基于表面细分技术的子波边界谱方法。它能精确描述复杂图形边界,提高处理复杂边界问题的能力和计算精度,把表面细分技术建立的几何模型直接用于边界谱方法的求解。数值算例表明,该方法是有效的。 展开更多
关键词 表面细分 子波 边界谱方法 声学
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运用边界状态约束的表面体素加密细分算法 被引量:3
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作者 刘晨燕 敬石开 +1 位作者 张伟 赵芳垒 《计算机集成制造系统》 EI CSCD 北大核心 2020年第4期970-979,共10页
为了平衡体素模型的体素数量与精细度,提出一种实体模型体素加密细化算法。该算法对低分辨率均一体素模型的表面体素进行切分,标记与三角面不相交的体素,并运用边界状态传递判定标记体素的内外位置。通过编码不同八叉树的节点,并进行跨... 为了平衡体素模型的体素数量与精细度,提出一种实体模型体素加密细化算法。该算法对低分辨率均一体素模型的表面体素进行切分,标记与三角面不相交的体素,并运用边界状态传递判定标记体素的内外位置。通过编码不同八叉树的节点,并进行跨八叉树快速邻居节点搜寻,实现多级加密细分。实验结果表明,该算法可以以低分辨率模型为基础,精确地获得体素单元少的高分辨率模型。 展开更多
关键词 表面细分 多分辨率 体素化 边界状态约束算法
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倾斜摄影模型优化和动态加载的关键技术研究 被引量:1
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作者 王昱霏 李绍彬 《计算机仿真》 北大核心 2023年第11期279-283,共5页
针对元宇宙环境中使用倾斜摄影模型构建大规模三维场景时,数据量过大和实时渲染困难的问题,提出了一种模型数据优化和动态加载的方法。方法将大量的倾斜摄影顶层数据进行重新划分,并优化合并后的几何与纹理数据,从而大幅度降低了渲染的... 针对元宇宙环境中使用倾斜摄影模型构建大规模三维场景时,数据量过大和实时渲染困难的问题,提出了一种模型数据优化和动态加载的方法。方法将大量的倾斜摄影顶层数据进行重新划分,并优化合并后的几何与纹理数据,从而大幅度降低了渲染的数据压力。同时,提出针对性的瓦片动态调度算法,以及基于表面细分的实时渲染优化策略,在确保原始数据不受损失的前提下,实现了高效和稳定的倾斜摄影数据处理和渲染方法。借助这一方法,开发了一套倾斜摄影场景优化和显示系统。实验表明,上述系统具有加载速度快,运行速度快,渲染效果好的特点,可以支持数百GB以至TB级别数据的调度,可以用于各种元宇宙和数字孪生场景当中。 展开更多
关键词 元宇宙 倾斜摄影 动态调度 表面细分
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非均匀有理B样条曲线在工业建模中的优势 被引量:4
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作者 朱险峰 孙颖莹 《浙江工程学院学报》 2003年第4期270-272,共3页
从工业建模的需求出发,对主流建模手段多边形、NURBS与细分表面进行了对比。NURBS建模手段因在精确性、控制性和系统资源占用率的平衡性最优而确定为最终技术方案,以完成设计与建模任务。
关键词 非均匀有理B样条曲线 NURBS 多边形 细分表面 工业设计 建模方法
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一种用于软组织变形仿真的动态质点弹簧模型 被引量:31
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作者 鲍春波 王博亮 +1 位作者 刘卓 程明 《系统仿真学报》 EI CAS CSCD 北大核心 2006年第4期847-851,855,共6页
针对可以用面模型近似表示的软组织,提出一种简单可靠的软组织变形仿真的质点弹簧建模方法。虚拟体弹簧动态地产生一种约束力表现软体的体特征,准静态方法求解模型使仿真效果更好;用修改的蝶形细分方法把比较粗糙的表面网格模型先细分... 针对可以用面模型近似表示的软组织,提出一种简单可靠的软组织变形仿真的质点弹簧建模方法。虚拟体弹簧动态地产生一种约束力表现软体的体特征,准静态方法求解模型使仿真效果更好;用修改的蝶形细分方法把比较粗糙的表面网格模型先细分成若干细节层次,仿真时依质点所受力的大小动态细分,以提高模型仿真的精确度。实验表明:所提出的方法确实增强了软组织变形仿真的体积感;局部动态细分模型与粗网格模型的计算量相差甚少,但其计算精度却提高多倍。 展开更多
关键词 质点弹簧模型 虚拟体弹簧 表面网格细分 物理建模 软组织变形 实时仿真
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A Review on the Biological Characteristics and Secretory Functions of Adipose-derived Mesenchymal Stem Cells 被引量:2
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作者 刘雪婷 支晓亮 +2 位作者 白春雨 张明海 关伟军 《Agricultural Science & Technology》 CAS 2016年第6期1331-1335,共5页
Adipose-derived mesenchymal stem cells (ADSCs) can be largely and easily obtained from a wide range of sources. Moreover, they have self-renewal ability, multi-differentiation potential, and an important role in imm... Adipose-derived mesenchymal stem cells (ADSCs) can be largely and easily obtained from a wide range of sources. Moreover, they have self-renewal ability, multi-differentiation potential, and an important role in immune regulation. They can secrete a variety of cytokines to regulate the in vivo micro-environment. Therefore, ADSCs are the ideal seed ceils for stem ceils application. This paper reviews the location, isolation, surface markers, proliferation, differentiation and other biological characteristics of ADSCs, as well as their secretory function and relative researches. ADSCs are expected to become excellent seed cells for cell therapy and tissue engineering through in-depth studies. 展开更多
关键词 Adipose-derived mesenchymal stem cell Surface markers Proliteration and differentiation Immune regulation SECRETION
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Surface plasmon resonance analysis to evaluate the importance of heparin sulfate groups' binding with human aFGF and bFGF 被引量:7
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作者 吴小锋 许雅香 +3 位作者 沈国新 KAMEIKaeko TAKANORyo HARASaburo 《Journal of Zhejiang University Science》 CSCD 2003年第1期86-94,共9页
Human acidic and basic fibroblast growth factors (aFGF and bFGF) are classic and well characterized members of the heparin binding growth factor family. Heparin is generally thought to play an extremely important rol... Human acidic and basic fibroblast growth factors (aFGF and bFGF) are classic and well characterized members of the heparin binding growth factor family. Heparin is generally thought to play an extremely important role in regulating aFGF and bFGF bioactivities through its strong binding with them. In order to unravel the mechanism of the interactions between heparin and FGFs, and evaluate the importance of heparin sulfate groups' binding with FGFs, surface plasmon resonance analyses were performed using IAsys Cuvettes System. Heparin and its regioselectively desulfated derivatives were immobilized on the cuvettes. aFGF and bFGF solutions with different concentrations were pipetted into the cuvettes and the progress of the interaction was monitored in real\|time by Windows based software, yielding kinetic and equilibrium constants for these interactions. In addition, in order to reduce the delicate difference among the cuvettes, inhibition analyses of mixture of FGFs and immobilized native heparin by modified heparins were also done. The data from these two methods were similar, indicating that all sulfate groups at 2 O, 6 O and N in heparin were required for the binding to aFGF; and that their contribution to the binding was in the order 2 O, N and 6 O sulfate group. In contrast, definite contribution of the 6 O sulfate group to the binding with bFGF was most apparent, while the other two sulfate groups appeared to be necessary in the order 2 O and N sulfate group. These methods established here can be used for analysing the effect of sulfate groups in heparin on the binding with other human FGF members or other heparin binding proteins. 展开更多
关键词 Surface plasmon resonance analyses HEPARIN Sulfate groups Human aFGF and bFGF
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Isolation and identification of bacteria associated with the surfaces of several algal species 被引量:4
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作者 王子峰 肖天 +2 位作者 逄少军 刘敏 岳海东 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2009年第3期487-492,共6页
We conducted this study to assess the diversity of bacteria associated with the surfaces of algae based on 16S rDNA sequence analyses.Twelve strains of bacteria were obtained from the surfaces of the following four sp... We conducted this study to assess the diversity of bacteria associated with the surfaces of algae based on 16S rDNA sequence analyses.Twelve strains of bacteria were obtained from the surfaces of the following four species of algae:Gracilaria textorii,Ulva pertusa,Laminaria japonica,and Polysiphonia urceolata.The isolated strains of bacteria can be divided into two groups:Halomonas and Vibrio,in physiology,biochemical characteristics and 16S rDNA sequence analyses.The phylogenetic tree constructed based on 16S rDNA sequences of the isolates shows four obvious clusters,Halomonas venusta,Vibrio tasmaniensis,Vibrio lentus,and Vibrio splendidus.Isolates from the surface of P.urceolata are more abundant and diverse,of which strains P9 and P28 have a 16S rDNA sequence very similar(97.5%-99.8%) to that of V.splendidus.On the contrary,the isolates from the surfaces of G.textorii,U.pertusa and L.japonica are quite simple and distribute on different branches of the phylogenetic tree.In overall,the results of this study indicate that the genetic relationships among the isolates are quite close and display a certain level of host species specificity,and alga-associated bacteria species are algal species specific. 展开更多
关键词 epiphytic bacteria ALGAE 16S rRNA gene PHYLOGENY
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Measuring Telomere Length in Proliferating Cells by Flow-FISH Method
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作者 Vyacheslav Borisov Olga Korolkova +3 位作者 Elena Blinova Denis Baev Vladimir Kozhevnikov Vladimir Kozlov 《Journal of Life Sciences》 2012年第8期945-951,共7页
The purpose of present work is a measurement of telomere length dynamic in proliferating cells in vitro by modified flow-FISH method. This method is a combination of two modifications: telomere length measurement in ... The purpose of present work is a measurement of telomere length dynamic in proliferating cells in vitro by modified flow-FISH method. This method is a combination of two modifications: telomere length measurement in differentiated cells by surface antigen and analysis of cells divisions' number by vital dye dilution. Lymphocytes were activated by anti-CD3 Abs with IL-2 presents and grown in vitro for 7 days. Cells division's number was measured by dilution of CFSE vital dye which cells were stained previously activation. For telomere length measurement we used flow-FISH method with Cy3 labeled telomere PNH probe. Using this method we evaluated the dynamic of telomere length in CD4+ and CD8+ T-cells after 7 days culturing in vitro and revealed the difference in telomere lengthening and shortening versus division rounds in cell subsets. In CD8+ cells telomeres start lengthen on a second division with the maximum on 4th division round becoming more that 20% longer compared with undividing cells. In CD4+ cells telomeres did not have any length peculiarities through all division rounds demonstrating different telomere regulation in subsets. This probably occurs due to the higher level ofhTERT protein expression in CD8+ than CD4+ cells do. 展开更多
关键词 Cell senescence telomere length flow-FISH CDSE lymphocytes.
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Research on the effect of the component proportion in the new water mist additive on firefighting performance 被引量:1
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作者 Ji Huanle Zhang Qingsong +1 位作者 Wu Binbin Liang Tianshui 《Engineering Sciences》 EI 2013年第6期85-90,共6页
Water mist technology provides efficient firefighting performance while there is still room for improvement. So varieties of additives have been studied in recent years both at home and abroad. The self-made additives... Water mist technology provides efficient firefighting performance while there is still room for improvement. So varieties of additives have been studied in recent years both at home and abroad. The self-made additives are used to compare the firefighting performance of diesel and heptane fire in open space. By adjusting the concentration of substance in the additives and conducting the experiment under the pressure of 0.3 MPa,0.5 MPa and 0.7 MPa,extinguish time and temperature are measured in the experiment. Through the experiments using different fuels,it can be found when the fuel is heptane that has a lower ignition point and a higher evaporation rate, the water mist additive can still significantly improve the firefighting performance. According to the data based on different concentrations of fluorinated surfactants,we find that fluorinated surfactants are the main substance to improve the performances by changing physical property of water mist. Optimal proportion of the additives for firefighting performance is found by experiment results. 展开更多
关键词 water mist additive firefighting performance additive proportion fire extinguishing mechanisms
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Biodegradation of n-hexadecane by bacterial strains B1 and B2 isolated from petroleum-contaminated soil 被引量:5
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作者 LIU Tao WANG FengHua +3 位作者 GUO LanPing LI XiaoLiang YANG XiaoJin LIN Ai Jun 《Science China Chemistry》 SCIE EI CAS 2012年第9期1968-1975,共8页
Two hydrocarbon-biodegrading bacterial strains, B1 and B2, were isolated from petroleum-contaminated soil collected from Tianjin, China. The strains were identified as Pseudomonas aeruginosa (B 1) and Acinetobacter ... Two hydrocarbon-biodegrading bacterial strains, B1 and B2, were isolated from petroleum-contaminated soil collected from Tianjin, China. The strains were identified as Pseudomonas aeruginosa (B 1) and Acinetobacter junii (B2). The degradation rate of n-hexadecane by BI and B2 reached 96% and 78% respectively after 7 days, though the strains employed different mechanisms of degradation. The results showed that B2 was not able to use glucose as carbon source. B 1 could produce glyco- lipid surfactants using glucose as the carbon source, according to the results of blue agar plate analysis and thin layer chroma- tography (TLC), and the bacterial culture of B 1 had a high oil discharge and emulsification activity. Both B I and B2 could produce biosurfactants with hexadecane as the sole carbon source, but their modes of action were different. The carbon source was found to affect the cell surface hydrophobicity. Cell surface hydrophobicity was poor with glucose as the carbon source, but enhanced when hexadecane was used as the carbon source. 展开更多
关键词 HEXADECANE BIOSURFACTANT HYDROPHOBICITY EMULSIFICATION bacteria
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Experiment on surface charge distribution of fine sediment 被引量:13
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作者 HUANG Lei FANG HongWei CHEN MingHong 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第4期1146-1152,共7页
Surface charge distribution of particles is the fundamental problem for adsorption and desorption between sediment and contaminant. In this paper, we take quartz sand for example to measure its micro-morphology and su... Surface charge distribution of particles is the fundamental problem for adsorption and desorption between sediment and contaminant. In this paper, we take quartz sand for example to measure its micro-morphology and surface charge distribution using the phase mode of the electrical force microscope. Then the statistical relation of micro-morphology and surface charge distribution is obtained. Results show that quartz sand possesses complex surface morphology, which has great impact on the charge distribution. Positive and negative charges mostly concentrate on the saddle, convex and concave parts of the surface, while distribute less in the groove, ridge and flat parts. This experiment provides a new method for understanding the process of flocculation in coastal and estuarine zone. 展开更多
关键词 SEDIMENT surface charge MICRO-MORPHOLOGY
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