演化地
- 与 演化地 相关的网络例句 [注:此内容来源于网络,仅供参考]
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But they remained skeptical of his selectionist reasoning -- that tiny random improvements were all there was to it -- because they felt Darwin 's explanation did not accurately fit the facts of nature, facts with which they were intimately familiar in a way that is rare today in this era of specialization and indoor laboratories.
但是,对于他用自然选择说来解释演化的机理――一切都只源于随机取得而累积的微小进步――仍很怀疑,因为他们觉得达尔文的说法不能准确地对应自然现实,那种现实他们再熟悉不过了,是那个年代的博物学家用专业分类和书斋研究的方法所观察到的(虽然我们现代已很少采用那些方法)[8]。
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This suggests that the ability to make others laugh has evolved at least in part through sexual selection.
这表明 逗笑他人的能力至少部分地通过性选择演化了。
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Comparing the unsteady flow fields obtained by CFD with the measurement results with SPIV, it can be found that the CFD results can capture the main characteristics of the flow fields observed in the experiment results, however, the precision of the CFD needs to be further improved, and to predict the detail flow structures, such as the tip leakage vortex in the compressor rotor, by CFD still has some difficulties, thus, some work should be done to improve the turbulence model for more accuracy prediction of the flow fields by CFD for the complex flow in turbomachinery.
定常计算结果和非定常计算结果都不能很好地反映出转子叶尖泄漏流,转子尾迹和泄漏流在静子通道中的演化,及其与静子的相互作用等复杂流动情况。开展叶轮机适用的湍流模型研究,对于提高叶轮机内部复杂流动数值模拟的准确性具有非常重要的价值。
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To overcome the difficulties and drawbacks in modeling the dynamic systems by using traditional methods, a hybrid evolutionary modeling algorithm is proposed to model the dynamic system with a system of ordinary differential equations whose main idea is to embed genetic algorithm in genetic programming where GP is employed to optimize the structure of a model, and GA is employed to optimize the parameters of a model.
针对采用传统方法解决动态系统的微分方程建模问题所遇到的困难和存在的不足,文中设计了将遗传程序设计与遗传算法相嵌套的混合演化建模算法,以遗传程序设计优化模型结构,以遗传算法优化模型参数,成功地实现了动态系统的常微分方程组建模过程自动化。
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To overcome the difficulties and the draw backs in modeling dynamic systems by traditional methods, a hybrid evolutionary modeling algorithm was proposed to model the Dynamic system with a system of ordinary differential equations whose main idea was to embed string coded idea and evolution algorithm optimize system.
针对传统方法解决动态系统微分方程建模问题所遇到的困难和存在的不足,设计将方程进行串结构编码并用进化方法进行演化建模的算法,以串形结构表示结构,用进化算法优化结构和参数,成功地实现了动态系统的常微分方程组建模过程的自动化。
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There is a new scientific theory of evolution-the theory of cellular automata : A simple procedure could be evolving into complex patterns can be accurately and easily simulate a variety of complex phenomena, from the growth of snowflakes to the universe, such as the evolution of the theory of evolution -- but often overlooked all their background-environment system stability and the supporting role of the smart set!
有一种新科学进化论-元胞自动机理论证明:一种简单但可演变出复杂样式的程序能精确、轻易地模拟出各种复杂现象,诸如从雪花的增长到宇宙的演化---然而所有的进化论往往忽略了其背景-环境系统的稳定而智能的支撑作用!
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In chapter 1, an up to now synthetically evaluation is given on the research ways and conclusions about jet in cross-flow. Considering the shortage of previous research ways and techniques (the instantaneous flow field and vortices field can not be properly get), in addition to the deficiency of corresponding conclusion (mainly concentrate on the analysis of time-average but little on structures of flow and action of vortex), the research way and content is draft out in this part. Though PIV, the time-average, instantaneous flow field and vortices field can be get, that will unveil the coherent vortex and its course of generation, development and evolvement, with the assistance of K-ε model and Hybrid Finite Analytic Method , which will proof-test the experiment result and bring some complementary, more profound research about the 3-D characters can be done. Using some fundamental topological theory and principle on flow analysis, with anglicizing of vortex structure, a reasonable description is the topological characteristic of near field in JICF given.
首先在第一章中对横流中湍射流的以往研究方法和研究成果给予了综合的评述,针对横流中湍射流旋涡结构以往研究中研究方法的局限性(不能很好得到流动的瞬态流场及涡量场)和相应研究成果中存在的不足(大都集中在时均特性的分析,对流动的内部结构和旋涡的运动阐述很少),明确了本文的研究方法和研究内容:通过PIV流动测量显示技术得到流动的时均及瞬态流场、涡量场,来揭示横流中湍射流的时均、瞬态流场、涡量分布特性,和各种具有拟序结构性质的复杂涡系的产生、发展及演化过程;结合湍流k-ε双方程模型及相应的HFAM计算方法,对于实验进行相互验证和补充,从而更为充分地研究各种旋涡的三维特性;利用拓扑分析的一些基本原理及相关规则,依据对各种旋涡结构的分析,做出对射流近区流场拓扑性质的合理描述。
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Beginning with wave equation, the paper has deduced the propagation of gauss pulses in single mode fiber and fiber grating transmission compensation. The characteristics of cascaded phase-shift gratings are discussed by numerical simulations of coupled-mode theory and T-matrix method. The experimental works and measurement results are shown in this paper. On the other hand, we have introduced the basic theory of EDFA and figured out the characteristics for EDFA at different conditions by numerical simulation. Some experimental results for EDFA are also presented here. In this article, you can find the influence on Optical Fiber Amplifier by Gain Tilt, especially, the negative effect on CSO in CATV transmission system.
论文首先从波动方程入手,对高斯脉冲在单模光纤中的传播演化及光纤光栅透射补偿进行了详细的研究;较系统地介绍了光纤光栅的耦合模理论,并将传输矩阵计算法用于计算级连相移光纤光栅的光学特性;重点介绍了作者在光纤光栅刻制及特性测量方面所做的一些实验研究工作;较系统介绍了EDFA的基本理论,计算出各种条件下EDFA的光学特性,并进行了一些实验研究;综合分析光纤放大器对光纤传输系统的影响,特别分析了光纤放大器增益不平坦对光纤CATV系统中CSO恶化的原因及其解决方法,并研究了光纤布拉格光栅在稳定980nm泵浦源输出功率和输出波长方面的应用;结合一个基于光纤光栅和光纤放大器的光纤用户接入网方案,对光纤用户接入网的若干问题进行了理论与初步的实验研究。
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And I also point out that the reason of occurrence of this phenomenon is that the seven representations of unlawfulness of the 54th provision adopt different criterions of classification.
合理性审查原则本身就是为了监控行政裁量权的目的而存在的,其涵义演化也是为了更好地监控行政裁量权。
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In order to study the thermal evolution of the Barbados accretionary complex,spatial coordinate and material coordinate are combined to handle the problem ofadvective heat transfer produced by tectonic movements.
为研究巴巴多斯增生复合体构造热演化的过程,采用空间坐标系和质点坐标系相结合的方法,在处理构造运动和变形的平流热效应时,并用变网格法及固定网格中的迎风法,成功地对该区域进行了二维有限单元法热模拟。
- 推荐网络例句
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Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).
呼气,收缩臀部肌肉;拱起身体,尽量抬起头来,右腿伸直朝向天花板(膝微屈,以避免肌肉紧张)。
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The cost of moving grain food products was unchanged from May, but year over year are up 8%.
粮食产品的运输费用与5月份相比没有变化,但却比去年同期高8%。
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However, to get a true quote, you will need to provide detailed personal and financial information.
然而,要让一个真正的引用,你需要提供详细的个人和财务信息。