查询词典 directivity

Its directivity of course is the development of its half finished product "individual" and the harmonious development of WTO world.

富有创造性地大胆提出"品牌教育"这一全新的概念和目标定位，使学生具备面向世界与未来民族素质、智能水平、价值取向和人格追求，形成既符合社会发展趋势，又符合人自身发展需要的发展能力。

A series of theoretical and experimental studies on the microstrip patch antennas with dielectric superstrates is carried out systematically. Firstly, a comprehensive survey of the microstrip antenna technology and its theories are presented. Then, two analysis techniques, named as the spectral domain Green's function method and the spectral domain integral equation method are developed. The SDGF method is a simplified analysis technique, which takes advantage of the spectral domain immittance approach to find the dyadic Green's function for the stratified media, and obtains the complete closed-form formulas for radiation patterns, directivity, efficiency, gain etc. Some interesting calculated results are presented. The SDIE method is capable of determining resonant frequency, radiation characteristics, input impedance etc, for the covered microstrip patch antennas. Comparing with other full-wave analyses it reduced computation and mathematical labour remarkably. The singularities near the pole location of the surface-wave modes and the difficulty of the integral computation over infinite range of oscillating integrands are dealt with actively and documented well. Results predicted by the SDIE method agree extremely well with our experimental results for resonant frequencies of various superstrates. The superstrate effects on impedance and radiation characteristics also have been investigated experimentally so that the gap due to lack of measured data and computed results for multi-layered superstrate has been filled to some degrees and two useful observations have been achieved for weakening the resonant frequency shift and optimizing the microstrip antenna gain. As a meaningful application, the design and analysis of a 4×4 patch array are introduced.

实用微带天线普遍加介质覆盖层来防护热，物理损伤和环境影响，也可能在飞行或严酷气候条件下自然形成覆盖层本论文对带介质覆盖层的微带贴片天线系统地作了一系列理论和实验研究首先，对微带天线技术和理论作了全面的综述然后，发展了两种分析方法，称为谱域格林函数法和谱域积分方程法SDGF法是一种简化的分析技术，它利用谱域导抗法来求得分层媒质的并矢格林函数，并得出方向图、方向性系数、增益等参数的完整的闭式公式，给出了一些令人感兴趣的计算结果SDIE法能确定介质覆盖微带天线的谐振频率、辐射特性和输入阻抗等与其它全波分析方法相比，它明显减小了计算量和数学工作量已有效地处理了表面波模极点附近的奇异性和对振荡的被积函数的无限区间积分计算的困难对于不同覆盖层情况下的谐振频率，由SDIE法所预示的结果与我们的实验结果吻合得很好对于覆盖层对阻抗和辐射特性的影响也已作了实验研究这在某种程度上填补了缺少实验数据和计算结果之间的间隙，并得出了缓解谐振频率偏移和优化天线增益的两点有用的结论作为有意义的应用，介绍了一个4×4元矩形贴片天线阵的设计和分析。

Because in "the space and time tunnel", the time has the directivity, the invertibility, may the clockwise, may also reverse, but may also relatively static.

因为在"时空隧道"里，时间具有方向性，可逆性，可以正转，也可倒转，还可以相对静止。

This article introduces the distribution of the internal ground fractures concluding the characters such as zonal distribution , irresistibility , directivity and periodicity .

文章详细介绍了我国地裂缝灾害的分布特征，总结出地裂缝具有成带性，不可抗拒性，方向性和周期性的灾害特点。

objective to study the intensity of magnetic field on a special meridian magnetic applicaˉtion.methods a special meridian magnetic application is found the variations of the intensity of magnetic field when it is in vitro,nipped by fingers and stuck on skin of meridian and non-meridian.results the variation of the inˉtensity of magnetic field and the difference of the two poles have a statistical significance when the special meridian magnetic applicationon straight line and interval10mm compares to on other conditions above.conclusion owing to a definite directivity of the magnetic field gradient is produced when the magnetic application on the meridians,it is hopeful to carry out the effects of the tonic and vent by acupuncture.

目的 研究循经传感磁疗贴的磁场强度变化。方法一种特制的磁疗贴，在体外、指捏、敷贴于皮肤表面的经络走行和非经络走行区时所测得的磁场强度变化。结果当该磁疗贴直线排列，间隔10mm时，与单独磁疗贴的初始相比，磁场强度发生明显变化，且具有两极差异；敷贴于皮肤经络走行区，与体外及非经络走行区相比，磁场强度变化显著，尤其在手阴经的走行区域，具有显著的统计学意义。结论该磁疗贴在经络走行线上形成的磁场梯度，具有明确的方向性，有望实现针刺产生的补与泄的作用。

RESULTS: The positive staining cells mostly included ependymal cells of myelocoele, glial cells, motor neurons, and epithelial cells of spinal pia mater. The staining was mainly located on the cell membrane. Most importantly, it displayed certain directivity in the glial cells, mainly at the membrane side contacting with capillary endothelial cells.

结果： 免疫组织化学染色结果显示阳性着色细胞包括有胶质细胞、中央管室管膜上皮细胞、脊髓前角运动神经元、软脊膜上皮细胞，着色部位主要在细胞膜，其中在胶质细胞表现出一定的方向性，主要分布在与毛细血管内皮细胞接触的一侧。

Results: the positive cells mostly included ependymal cells of myelocoele, glial cells, anterior horn motor neurons, and epithelial cells of spinal pia mater and their expressions were mainly located on cell membrane. interestingly, aqp4 distribution in glial cells and ependymal cells showed certain directivity, but the former was mainly in the membrane side contacting with capillary endothelial cells and the latter mostly in the basolateral membrane of ependymal cells.

结果： 免疫组织化学染色和原位杂交结果显示胶质细胞、前角运动神经元、中央管室管膜细胞、软脊膜上皮细胞均表达阳性，aqp4主要分布于细胞膜，其中，胶质细胞和中央管室管膜细胞表达存在极性，前者主要分布在与毛细血管内皮细胞接触的一侧，后者主要分布在中央管室管膜细胞的基底侧膜。

At the same value of frequency and size, the directivity of quadrate ring piston is sharper than that of quadrate piston.

在同一声波频率以及相同尺寸的情况下，方环活塞声源要比方形活塞声源的远场指向性更尖锐。

A new kind of excitation source model, which is more approximate practical situation, is presented. Based on the results, the input impedance, gain and directivity of a rhombic antenna is analyzed by using moment method and microwave network theory.

针对卫星通信拥挤、短时无法补充的缺陷，提出了一种新的更接近实际的平衡激励源处理方法，并在此基础上利用微波网络理论与矩量法相结合，系统地分析、计算了菱形天线的输入阻抗、增益及方向特性。

The establishment question situation, can spiritedly cause the classroom, the knowledge simple to be easy to understand, its intense practice directivity is extremely obvious.

创设问题的情境，能使课堂生动活泼、知识浅显易懂，其强烈的实践指向性是极其明显的。

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。