波前

In this method, fast Fourier transform is used as a converter between wavefront and its corresponding plane wave spectral.

在波前合成方面，本文根据傅立叶光学中平面波谱传播理论，给出了一种适合于平面波前的快速变换方法。

For the evolution of the forward density front of water-plasmas, it is found that the density front moves with supersonic speed at the beginning, as predicted by a hydrodynamics simulation.

此外在研究水等离子体在激光方向的前向动力学演化过程中发现，在早期等离子体密度波前以超声速运动，这和理论模拟一致。

Wavefront aberrations of the cornea were assessed preoperatively and 1 to 2 months postoperatively using a corneal topographer (Optikon-2000SpA) and a picture processor (Keratron-Scout).

使用Optikon-2000SpA角膜地形图仪和Keratron-Scout图像处理器，摄取手术前和手术后1~2个月的角膜波前像差。

The WASCA aberrometer was used to measure the HOA before and 6 months after surgery in dark room condition.

使用Zeiss-WASCA客像差仪在术前和术后6月测量患眼暗室自然瞳孔下的波前像差。

A new subjective wave-front aberrometer, which measures ocular wave-front aberrations, is studied. The working principle and design project are presented.

研究了一种用于测量人眼波前像差的新型主观式波前像差仪，给出了工作原理和实现方案。

We considered that the method of spherical surface waves raytracing basing on the grid combined the virtues of the grid method. It is precise and high efficient in calculating traveltime and raytrace. It is a perfect method of raytracing.

分析认为，基于网格的球面波波前射线追踪方法结合网格法的优点，在计算走时和射线路径时精确、高效，是一种理想的射线追踪方法。

It is very difficult to realize expanding the working band of Hartmann-Shack wavefront sensor through Frequency Transfer of Nonlinear Optics. Usually three wave-mixing researches are based on plane wave or Gauss wave, so study of aberrated second harmonic generation is new and important. It could be very helpful to understand and make good use of the Frequency Transfer of Nonlinear Optics.

这说明利用非线性光学频率变换方法拓宽波前传感器件的响应波段是很难实现的，但是，通常三波相互作用过程的研究均是建立在平面波和理想高斯光束之上，因此我们对于位相畸变倍频过程的研究是非线性光学领域一个重要而有意义的新课题，它有助于人们更加深入理解非线性光学效应，为进一步合理利用之奠定了理论和实验的基础。

If the wavefronts are parallel lines, the waves are called plane waves.

假如波前为一些互相平行的轮廓面，这波就叫平面波。

Obviously,there is a little difference between the new wave front and the former plane.

作这些子波的包络，就得出新的波前。

Successive positions of the wave front are then given by the envelopes of the secondary waves.

因此波前的相继位置即为次波的包络面。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。