查询词典 mechanisms

Mechanisms concerning these cell cycle events are conserved from the simple mono-cell eukaryote to the complicated metazoan.

从最简单的单细胞真核生物酵母，到复杂的后生生物，例如我们人类自己，这些进行调控的分子事件都是高度保守的。

This project studies the scale-dependent deformation behavior of the metal matrix composite, the void nucleation and void growth mechanisms at the micron/submicron scale. The main results are:(1) In prophase, growth and coalescence of the void embedded in the graded matrix are analyzed in detailed;(2) Based on the infinite solid model containing a micro-void, coupling effects of the void shape and the void size on the void growth are studied carefully, the results show that it seems to exist a critical equivalent void radius, which is associated with the material length. When radius of a microvoid is close to or smaller than the critical void radius, the micro-void growth rate is essentially eliminated;(3) The coupling effects of the particle shape and size on the mesoscopic stress fields within the particle and matrix are also investigated by introducing the conception of inclusion/matrix interfacial energy. The results show that the stress concentration factors within the particle and on the matrix/particle interface are also strongly size-dependent,so the void nucleation mechanism is size-dependent.(4) By employing a specific orthogonal curve coordinate frame and a 'kernel function' conception, a 'unified method'solving the spheriodal and spherical void problems is suggested; by this unified method, size-dependent plastic potentials of the porous materials containing the spheriodal or spherical voids are obtained, which extend the traditional Gurson model for the spherical void and GLD model for the spheriodal voids to the micron scale.(5) Based on the RVE model containing the spheriodal or spherical particles, the influences of the particle shape and size on the size-dependent mechanical behavior of metal matrix composite are studied.

中文摘要：本项目对金属基复合材料在微细观尺度下的尺度相关变形行为、孔洞形核及长大的机理和模型进行了研究，取得了如下主要结果：1）在前期研究中，探讨了基体的梯度分布对孔洞长大和聚合的影响；2）基于含孔洞的无限大体模型，探讨了孔洞形状和孔洞尺寸对其长大的耦合作用，结果表明：可能存在一个与材料特征长度相关的临界孔洞尺寸，当椭球孔洞的等效半径小于临界孔洞半径时，孔洞的长大受到明显抑制；3）通过引入基体/夹杂界面能的概念，分析了夹杂尺寸、夹杂形状对材料细观应力场的耦合影响，结果表明：颗粒内部和界面上的应力集中因子强烈地依赖于夹杂的尺寸和形状，因此，孔洞的形核机理是尺寸相关的；4）采用一种特殊的正交曲线坐标系和引入"核函数"的概念，"统一"地得到了含椭球和球形孔洞的材料的尺寸相关塑性势，它将传统的Gurson球形孔洞模型和GLD椭球孔洞模型推广到微尺度范围；5）基于含椭球和球形夹杂的体胞模型，初步研究了夹杂形状、夹杂尺寸对金属基复合材料尺寸相关力学行为的影响。

Methylation of CpG Islands is one of the most important mechanisms in the epigenetic regulation of gene expression.

CpG岛的甲基化是表观遗传中基因表达调控的重要机制。

SQR can lead to a decrease in blood viscosity and improve the blood flow, which may be one of the mechanisms of SQR in treating metrorrhagia after copper IUD insertion.

改善血液流变性可能是SQR防治宫环出血病的机制之一。

Metallographic analysis, analysis for fracture surface of scanning electron microcopy photographs, electron-probe analysis,X-ray powder diffraction analysis, transmission electron microscope analysis have been done for the analysis of microstructurs、fracture apperance、structure,and has carried on the preliminary discussion to the toughening Mechanisms.

采用金相分析、扫描断口分析、能谱分析、x射线粉末衍射结构分析、透射电镜分析对合金化以及引入韧性第二相后的TiFe_2合金的显微组织、断口形貌、微观结构进行了分析，并对合金的韧化机制进行了初步的探讨。

The purpose of this study is to investigate the effects of H2S on electrophysiology of ischemic cardiomycytes and its underlying mechanisms by using intracellular microelectrode technique.

本研究旨在通过应用细胞内微电极技术观察H2S对于缺血不同时期心肌细胞电生理效应，并探讨其可能的作用机制。

In microevolution, it provided a number of molecular marker systems for the research of genetic variation in plant natural populations, greatly facilitating investigation of the evolutionary mechanisms under natural conditions.

它们在研究植物天然居群遗传变异的规律、揭示进化机制方面已展示了巨大潜力，这是进化生物学中最重要的研究领域之一，也是物种遗传多样性保护的理论基础。

The finding of this two ecotypes of Sedum alfredii Hance is of importance for understanding physiology, biochemical and microevolution mechanisms of Zn tolerance and hyperaccumulation of plants.

这两种生态型东南景天的发现，为今后探讨植物耐高Zn胁迫和超积累Zn的生理生化机制和植物抗高锌胁迫的微进化过程提供了非常有价值的材料。

The results also show that the corroded processes of the glasses in different solutions have their own characteristics The different processes are described in details and mechanisms are discussed by means of micrography and XRD techniques.

利用显微照相和XRD等测试手段对不同的侵蚀过程进行了描述并讨论机理。

In this thesis, the mechanical properties of PVC/Al_2O_3 nano-filler composites were researched. And the relationship between microscopic deformation mechanisms and macroscopic mechanical properties was investigated by micromechanics method and finite element methods.

本论文对制备的PVC／纳米Al_2O_3复合材料进行了力学性能测试，主要利用细观力学方法和有限元数值分析方法研究了复合材料微观变形机理和宏观力学性能之间的关系。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。