方向余弦

The abscissa at the endpoint of an arc of a unit circle centered at the origin of a Cartesian coordinate system, the arc being of length x and measured counterclockwise from the point(1,0) if x is positive or clockwise if x is negative.

余弦以笛卡儿坐标系原点为圆心的单位圆的圆弦端点的横坐标，弧的长度为x，如果x为正，弧的长度则从（1，0）点按逆时针方向算起，若x为负，则按顺时针方向从（1，0）点算起

The abscissa at the endpoint of an arc of a unit circle centered at the origin of a Cartesian coordinate system,the arc being of length x and measured counter clockwise from the point(1,0)if x is positive or clockwise if x is negative.

余弦以笛卡儿坐标系原点为圆心的单位圆的圆弦端点的横坐标，弧的长度为x，如果x为正，弧的长度则从(1，0)点按逆时针方向算起，若x为负，则按顺时针方向从(1，0)点算起

According to the Source attenuation model, Lambert′s cosine law of diffuse reflection and Phong specular reflection model, 2 equations used to calculate the opacity and intensity of every voxel in the volume data were obtained.

方法由源衰减模型、朗伯漫反射余弦定律和Phong镜面反射模型，推导出计算数据场中每一点的不透明度和明暗度的计算公式，通过旋转光源和视点，来自不同观察方向的感兴趣结构的体绘图被满意地生成。

By adjusting the weight, different component in the volume can be filtered out. According to the Source-attenuation model, Lambert's cosine law of diffuse reflection and Phong specular-reflection model, two equations used to calculate the intensity of every voxel in the volume data are obtained.

由源-衰减模型，朗伯漫反射余弦定律和Phong镜面反射模型，推导出了计算数据场中每一点明暗度的计算公式，通过旋转光源和视点，来自不同观察方向的感兴趣结构的体绘图能被满意地生成，从而避免了对内存中整个体数据的旋转。

The information Radon coefficient wrap-around of the line on a finite field was caused by the modular arithmetic so that the Radon coefficient information in the periodic oscillations direction was processed with discrete cosine transformation, and other direction information was processed with wavelet analysis in order to reduce the wrap-around of rebuilding information. At the same time, according to the characteristic of the noise, one kind of denoising threshold selection plan was proposed.

正交有限脊波分析处理信息时，有限域平面上的直线由于模运算的存在而引起信息Radon系数的卷绕，为此，对Radon系数周期振荡方向的信息采用离散余弦变换处理，其他方向信息采用小波分析处理，以减少卷绕对信息重建影响；同时，结合图像信息中噪声的特点，提出了一种去噪浮动阈值的选取方案。

The first, look like each detail picture of direction of picture and each layers to carry on DCT towards get of again, then will imbed to look like the son diagram DCT transformation through two value watermark pictures of the false random row preface behind of the part of the high part of frequency and the detail son diagram energy concentration.

本论文中提出的第一种算法是一种基于离散余弦变换和离散小波变换相结合的脆弱水印方法，即：先对图像进行离散小波变换，再对得到的近似图像和各层各方向的细节图像进行离散余弦变换，然后将经过伪随机排序的二值水印图像嵌入到近似子图DCT变换后的高频部分和细节子图能量集中的部分。

The sine and cosine signals induced on stator are amplified by instrumentation amplifier and connected to the converter AD2S83, which is designed according to tracking goniometry. Digital logic control and address encoding are processed by FPGA, and the converted 16-bit parallel angle data and direction signal are transferred to DSP.

本设计中通过RC 振荡电路为感应同步器转子提供单相激磁信号，定子上感应出来的正弦和余弦两路信号通过仪表放大器的差分放大之后提供给基于跟踪型测角原理的转换芯片AD2S83，通过FPGA 实现数字逻辑控制以及地址解码，将转换后的16 位并行转角数据以及方向信号送入DSP 中。

In this design, a single-phase exciting signal generated by RC oscillatory circuit is applied to the rotor of synchro. The sine and cosine signals induced on stator are amplified by instrumentation amplifier and connected to the converter AD2S83, which is designed according to tracking goniometry. Digital logic control and address encoding are processed by FPGA, and the converted 16-bit parallel angle data and direction signal are transferred to DSP.

本设计中通过RC振荡电路为感应同步器转子提供单相激磁信号，定子上感应出来的正弦和余弦两路信号通过仪表放大器的差分放大之后提供给基于跟踪型测角原理的转换芯片AD2S83，通过FPGA实现数字逻辑控制以及地址解码，将转换后的16位并行转角数据以及方向信号送入DSP中。

In this design, a single-phase exciting signal gener AT ed by RC oscill AT ory circuit is applied to the rotor of synchro. The sine and cosine signals induced on st AT or are amplified by instrument AT ion amplifier and connected to the converter AD2S83, which is designed according to tracking goniometry. Digital logic control and address encoding are processed by FPGA , and the converted 16-bit parallel angle d AT a and direction signal are transferred to DSP.

本设计中通过RC振荡电路为感应同步器转子提供单相激磁信号，定子上感应出来的正弦和余弦两路信号通过仪表放大器的差分放大之后提供给基于跟踪型测角原理的转换芯片AD2S83，通过 FPGA 实现数字逻辑控制以及地址解码，将转换后的16位并行转角数据以及方向信号送入DSP中。

The charts of velocity vector of flow field outside the tube under five conditions with amplitude 1.3 mm and frequency 5—25 Hz were obtained,and the cosine of average synergy angle of flow field outside the tube was calculated.

实验及模拟结果表明：振动能够显著增加管外近壁区的流体速度，能够在振动方向上的管壁两侧形成有效的冲刷，随着振动频率的升高其管外近壁区的平均速度近似呈线性增加，在共振点出现峰值；相同区域内振动工况的平均场协同角余弦值要明显大于无振动工况，但不同振动频率间的场协同角余弦值变化较小。

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。