定向

BACKGROUND: Directional differentiation of bone marrow mesenchymal stem cells requires regulation of appropriate growth factors.

摘要背景：骨髓间充质干细胞的定向分化需要合适生长因子的调控，利用细胞因子基因转染促进其生长、定向分化和加速骨缺损修复是近年来研究热点。

Objective To establish the spontaneous differentiation culture system of embryonic stem cells in vitro and provide methodological and morphological basis for the directional differentiation of ES cells.

目的建立胚胎干细胞(embryonicstemcells，EScells)体外非定向分化培养系统，为其向各种成熟细胞的定向诱导分化提供方法学和形态学基础。

Effect of high vertical magnetic field on the directional solidification structure of eutectic MnBi/Bi has been investigated.

进行了纵向强磁场下MnBi/Bi共晶定向凝固实验研究，并从热力学的角度分析了强磁场对 MnBi/Bi共晶定向凝固组织的影响。

Firstly, four beams are formed using wideband distortionless beamforming method, which divides the whole space into four separated regions. Then the beam outputs are calculated and taken as the signal received by a reference point.

该方法首先预形成指向4个方向的宽带无失真波束，各自的主瓣区域把整个空间分为4个不同的测量区，然后分别将这4个波束形成器的波束输出作为参考点接收到的声信号，利用基于时延的定向方法定向处于不同测量区的声源。

Under the existing condition of the lab, a lot of experiments, analyzing and improving are made. Now, the problems in photoengraving, sputtering and diffusion etc. have been solved elementally. Excellent technological parameters are achieved and 2×2 LiNbO3 waveguide optical switch has been fabricated successfully. At the end of this paper, the losses of 2×2 LiNbO3 waveguide type optical switch are analyzed. The testing system is established. The V-grooves used for coupling have been designed.

我们在现有的实验条件下，经过反复实验，分析和改进，克服了光刻，溅射，扩散等各个阶段中的难题，总结出各部分最优的工艺参数，制备出了2×2定向耦合器型光波导开关，在本文的最后对制备出的光波导开关的各种损耗进行了分析，建立了测试系统，对光开关进行了通光测试，并对本2×2定向耦合器型光波导开关以后的耦合封装V型槽进行了设计。

Firstly, it examine (1) the foundation of Erikson's self-identity concept and theory, and (2) the establishment of the operational definition of self-identity and the theory on self-identity statuses, and (3) the development of Neo-Eriksonian self-identity concept and theory by the developmental phases of Eriksonian self-identity concept and theory.

首先，按Erikson定向的自我同一性概念和理论的发展阶段考察了(1)Erikson自我同一性概念与理论的奠基；(2)自我同一性操作定义及自我同一性状态理论的确立；(3)新Erikson定向的自我同一性概念与理论的发展。

The ADWM filter has the features of directional filter, which is especially effective at preserving edges, and the features of center weighted median filter, which can reduce random noise, and moderate amounts of impulsive noise also, to some extent, as well as preserve the details via adaptively determining the weight of the center pixel according to the lowest variance of pixels within all the sub-windows.

ADWM滤波器既有定向滤波器的特征，也有中心加权中值滤波器的特征。定向滤波器可以有效保持边缘，而中心加权中值滤波器对减少随机噪声尤其有效，同时也能在一定程度上减少冲击噪声的数量，并根据子窗口内像素的最低方差自适应地调整中心像素的权值以保持图像的细节。

The ADWM filter has the features of directional filter, which is especially effective at preserving edges, and th e features of center weighted median filter, which can reduce random noise , and moderate amounts of impulsive noise also, to some extent, as well as p reserve the details via adaptively determining the weight of the center pixe l according to the lowest variance of pixels within all the sub-windows.

ADWM滤波器既有定向滤波器的特征，也有中心加权中值滤波器的特征。定向滤波器可以有效保持边缘，而中心加权中值滤波器对减少随机噪声尤其有效，同时也能在一定程度上减少冲击噪声的数量，并根据子窗口内像素的最低方差自适应地调整中心像素的权值以保持图像的细节。

The estimation errors, including the finite difference approximation error, the instrumentation channel mismatch error, and the error caused by ambient noise, are studied systematically.

文中基于声信号的空间互谱分析，给出了声强向量阵的定向原理，并系统分析了其定向误差，包括有限差分误差、通道失配误差和环境噪声引起的误差。

The propulsion control system is one of the four subsystems of theMaglev vehicle. The propulsion control theory with field-oriented control is the key technology of the propulsion control system. In this paper,the characteristics of Maglev vehicle propulsion control system with FOC aredeeply studied and analyzed.

牵引控制系统是高速磁悬浮列车四大子系统之一，基于磁场定向控制理论的牵引力控制又是牵引控制系统的核心技术，本文深入研究和分析了在不同磁场定向控制方式下高速磁悬浮列车的牵引特性。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。