关键

Here, we have developed vascular endothelial growth factor high-expressing, transiently modified stem cells for the purposes of promoting angiogenesis.

一个关键的问题在于经过改造的细胞不能产生足够数量的刺激血管生长的关键蛋白——诸如血管内皮生长因子。

This paper, which focused on the structure optimization theory and method, has finished such studies as follows: The three dimension model has been built, which provide the necessary conditions for the building of the dynamics equivalent model. By the launch dynamics simulation, the loads of the key joints when the rocket is launched has been got, which provide the necessary data for the finite element analysis and the structure optimization. The finite element model of the excess weight parts of the rocket has been built, buy the finite element intension analysis of the model in two conditions, the displacement and the stress of the key points have been got, which make us know the distributing of the stress and the transmogrification of the part. To satisfy the intension and the precision design request and to decrease the weight of the part as many as possible, the part has been topology optimized by the structure optimization theory and method. After that, the new model has been analysis in structure and launch dynamics. The contrast of the character change of the old part and the new part and the influence on the rocket system have been studied.

本文以结构优化理论和方法为核心，主要做了以下工作：建立了某自行火箭炮全炮三维实体模型，为建立该火箭炮系统的动力学等效模型提供了必要条件，进行了发射动力学仿真，得到该火箭炮发射装置各关键连接部位在发射状态下的载荷，为有限元分析和结构优化提供了必需的数据；建立了该火箭炮发射装置超重部分的有限元模型，分两种工况，对模型进行了有限元强度分析，得出了关键部位的位移和应力值，对其的应力和变形分布有了具体的了解；运用结构优化的理论和方法，对该火箭炮发射装置超重部分进行了拓扑优化，使其在满足强度和精度的要求下尽可能多地减轻重量，对优化后得到的模型进行了结构分析和发射动力学分析，对比了该部件优化前后的特性变化以及对火箭炮系统的影响。

In view of the fuzzy characteristics of real world, fuzzy set theory and statistics with vague data are combined to generalize key theorem and bounds on rate of uniform convergence of learning processes as the base of statistical learning theory in this thesis.

摘要考虑到现实世界的模糊性，本文结合模糊集理论和模糊统计学的知识，对作为统计学习理论基础的关键定理和学习过程一致收敛速度的界进行推广，给出了模糊学习理论的关键定理和一致收敛速度的界。

In addition, the concept of scene centriod is introduced to represent video scene by averaging of all key frames inside a group of shots in the given video scene, which makes an audacious attempt for high-level video unit extraction and representation;4 According to the given sample video, shot and scene-based video retrieval methods are discussed respectively, and the evaluation pricinples are also discussed.

进而，讨论了由场景中一组镜头的关键帧的质心表示场景关键帧，即场景质心的方法，从而为抽取高层的视频数据单元做出了大胆的尝试； d 从给定样本视频出发，分别讨论了基于镜头和场景的视频检索方法，并分析了检索性能评价的准则。

Therefore, different critical area extraction algorithms are developed according to different defect types With the concept of critical area, the unitarity of Monte Carlo method and critical area method is discussed in fault-sensitivity analysis.

并利用关键面积的概念，论述了Monte Carlo方法和关键面积方法在芯片故障敏感度分析中的统一性。

Press key # or key * to select/unselect current item.

新闻关键＃或关键*选择/取消当前的项目。

The second key technique is about exact vector representation of key raster primitives.

关键技术之二是准确地获取细化图像中关键图素的矢量表示。

This is realized by using critical flow venturi- nozzles and by controlling the critical flow inlet conditions to constant va...

该流量是柴油机气态排放和颗粒排放计算中的关键参数之一，是排放测试设备的关键技术。

It was a March to remember for Salomon Kalou.Saturday's lifeline late winner at Vicarage Road confirmed his status as Chelsea's most in-form net-finder with four goals in his seven appearances last month.

周六在维克雷奇路最后时刻的关键进球使他成为了切尔西最活跃的得分手之一，他在过去一个月的7场比赛中打进了4个关键进球。

Vii to actively promote the key links and key areas of reform.

积极推进的关键环节和关键领域的改革。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。