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241.
构成设计课,在整个艺术设计过程中,我认为起到了非常关键的作用,特别是立体构成课不但是基础与专业的衔接关键,更是通向服装设计的关键桥梁. 相似文献
242.
王祖龙 《湖北三峡学院学报》2007,29(5):101-104
楚国的造物品类繁多、主题鲜明、格调清奇灵秀、色彩斑斓繁艳,开创了上古南方审美文化的新视界。楚器物从造型到装饰所表现出来的楚风特征表明,楚器物的产生与楚风俗有着密切的关联,楚风俗是楚器物发育生长的母胎。 相似文献
243.
Zilin Li Zhaowei Zhu Xianglong Yu Kai Li Zixi Wang Zezhao Zhang Yuming Wang 《自然科学进展(英文版)》2021,31(2):255-263
This study aims to investigate tribological properties in a siliconized graphite(СГ-П-0.5) and hierarchically hybrid Si C/C composites at the load ranging from 10-40 N under dry air/water lubrication conditions. A feasible liquid silicon infiltration(LSI) was used to fabricate the Si C/C composites. Morphology and phase identification of two materials were characterized and analyzed by scanning electron microscope(SEM) and energy dispersive spectrometer(EDS). An image feature extraction was used to post-process the data of wear test, further to gain the wear properties of the samples. The results demonstrated that a lower coefficient of friction(COF) and wear rate can be achieved in the LSI Si C composites than that in the sample of СГ-П-0.5. Both COF decreased under waterlubricated conditions, compared with that under the dry air lubrication. The excellent tribological properties in two materials can be due mainly to the microstructure of the СГ-П-0.5 sample, showing much more graphite and Si dispersed on the matrix. The СГ-П-0.5 sample indicated the typical oxidative wear mechanism, whereas, the sample of LSI Si C demonstrated the combined oxidative and fatigue wear. This finding can provide a promising new siliconized graphite materials for ceramic rolling bearings. 相似文献
244.
This article addresses knowledge transfer dynamics in agent-based computational social science. The goal of the text is twofold. First, it describes the tensions arising from the convergence of different disciplinary traditions in the emergence of this new area of study and, second, it shows how these tensions are dealt with through the articulation of distinctive practices of knowledge production and transmission. To achieve this goal, three major instances of knowledge transfer dynamics in agent-based computational social science are analysed. The first instance is the emergence of the research field. Relations of knowledge transfer and cross-fertilisation between agent-based computational social science and wider and more established disciplinary areas: complexity science, computational science and social science, are discussed. The second instance is the approach to scientific modelling in the field. It is shown how the practice of agent-based modelling is affected by the conflicting coexistence of shared methodological commitments transferred from both empirical and formal disciplines. Lastly, the third instance pertains internal practices of knowledge production and transmission. Through the discussion of these practices, the tensions arising from converging dissimilar disciplinary traditions in agent-based computational social science are highlighted. 相似文献
245.
邱燕炜 《东华大学学报(自然科学版)》1999,(3)
通过时纤维的线密度引入平稳过程和窗函数两个概念,提出了纤维的一种数学模型.在此基础上,对理想纱条的假设条件作了减弱,建立了一种更具普遍意义的理想纱条的数学模型. 相似文献
246.
通过实地考察和分析.论述了太白国家森林公园的基本特征与功能.并时其建设与管理提出了具体的建议和措施。 相似文献
247.
通过动态监测油井分油层的产能可以掌握油井的生产状况,监测产能在油田生产中具有重要的意义.目前基于色谱指纹的产能预测越来越受到油田相关部门的重视,但是目前色谱指纹的选取还是依靠专业技术人员进行选取,这导致特征选取存在一定的主观性.到目前为止还没有研究者对色谱指纹特征的选择问题进行系统的研究.为了对色谱指纹特征选取问题进行分析,本文分别采用主成分分析(PCA)、线性相关以及随机森林中的重要性分析理论进行特征选取,最后提出了一种新的联合特征选取方法.对来自南海某油田的配比数据进行了测试,实验结果表明,本文提出的方法取得了很好的试验效果,在原油产能预测领域有较大的应用价值. 相似文献
248.
采用近红外光谱线性分析技术实现对鱼粉蛋白的快速检测,选择合适的波长变量是提高模型预测精度的关键。主要目的是建立一种稳健、简单的多元线性回归(MLR)模型,通过研究基于特征峰值的投影技术实现参与建模的波长优选。特征物质在近红外光谱区域的吸收特征,以鱼粉一阶导数光谱的峰谷波长点作为出发点,依次采用逐步多元线性回归(SMLR)和连续投影线性回归(SPA-MLR)方法完成两度特征信息波长筛选,进一步对备选的波长变量执行显著性检验,最终确定近红外线性分析的特征信息波长组合。结果表明,近红外长波区域中优选出53个特征信息波长变量,能够提高鱼粉蛋白近红外定量模型的预测精度,简化了模型,从而提高了模型的适用性和稳健性。 相似文献
249.
Visual Models in Analogical Problem Solving 总被引:1,自引:0,他引:1
Visual analogy is believed to be important in human problem solving. Yet, there are few computational models of visual analogy.
In this paper, we present a preliminary computational model of visual analogy in problem solving. The model is instantiated
in a computer program, called Galatea, which uses a language for representing and transferring visual information called Privlan.
We describe how the computational model can account for a small slice of a cognitive-historical analysis of Maxwell’s reasoning
about electromagnetism. 相似文献
250.
Platelet-activating factor acetylhydrolases (PAF-AHs, EC 3.1.1.47) constitute a unique and biologically important family
of phospholipase A2s. They are related to neither the well-characterized secretory nor cytosolic PLA2s, and unlike them do not require Ca2+ for catalytic activity. The distinguishing property of PAF-AHs is their unique substrate specificity they act on the phospholipid
platelet-activating factor (PAF), and in some cases on proinflammatory polar phospholipids, from which they remove a short
acyl moiety – acetyl in the case of PAF – located at the sn-2 position. Because PAF is found both in the plasma and in the cytosol of many tissues, PAF-acetylhydrolases are equally widely
distributed in an animal organism. Recent crystallographic studies shed new light on the complex structure-function relationships
in PAF-AHs.
Received 15 September 1997; received after revision 23 February 1998; accepted 25 February 1998 相似文献