精度

In experiment firstly used unsupervised classification to remote sensing image, made progress of manual work interpreted to make certain their attributes, then transformed their outcome to the file of classification cyclostyle, and then carried out supervised classification, it indicated that the classification precision of Poyang Lake wetland was improved through these means.

在监督分类中，采用了不同波段组合方式、主成分分析等手段，经过基于误差矩阵的精度评价分析表明，这些手段可以提高鄱阳湖湿地遥感影像分类的精度。

In mechanical industry, high precise coaxiality test of large mechanical components was considered as a complicated problem, because it was very difficult to find a datum line with high precise in long distance.

大型机械零部件同轴度高精度测量是机械行业的共性技术难题，其技术关键和难点在于建立长跨距的高精度测量基准线。

It is shown that in complex system like L-tyrosine, using a locally dense basis set with a large number of atomic basis functions for the carbon atom of interest and smaller sets of atomic functions for the other atoms can not only save the disk capacity and computing time but also produce satisfactory results.

由从头计算获得的结果与实验值符合较好，说明对于具有复杂结构的多原子体系，对杂原子使用较小的基函数，而对所关心的碳原子使用较大的基函数以提高计算精度，这样可以达到既节省计算机空间与计算时间而不影响计算精度的目的。

The polarization light used to affect the accuracy of optical test instrument, optical sensor and the quality of optical communication system, the depolarizer can be used to decrease the affection. Different kinds of depolarizer have different applications, so we need select proper kind of depolarizer for special application.

偏振光会对光学仪器测量精度、光通信系统传输质量及传感器精度产生影响，通常可以采用退偏器来减小这种影响，但每种退偏器都有一定的应用范围，要根据不同的应用来设计选择相应的退偏器类型。

And the Monte Carlo optimization approach is used to simulate the assembly accuracy. The accuracy based design method of robot assembly unit is studied and the configuration tolerance of valve peg-hole assembly unit is derived.

采用蒙特卡洛法进行了机器人装配的精度模拟，研究了基于精度的机器人装配单元的设计方法，并以气门轴孔装配单元为实例得到系统配置的公差要求。

Then the finite element software ANSYS is used to simulate the orthotropic flattened Brazilian disc specimen subjected to diametrical compression, the accuracy of the approximate formula of compression displacement is checked. The formula is further modified with a semi-empirical and semi-analytical approach, and it is shown to have better accuracy than the original formula covering the whole range of orthotropic anisotropic index of rock, the error is less than 6%.

用有限元分析软件ANSYS模拟正交异性岩石的巴西圆盘试样的对径压缩实验；利用有限元分析结果对正交异性平台位移压缩公式进行精度检验，并用半经验半解析的方法，对该公式进行局部的修改，修改后的公式在岩石材料的正交异性指数的整个范围的总体评价上，误差小于6%，具有更好的计算精度。

The validity of staggered grid real value FFT differentiation operator is confirmed by comparing with the analytic Cagniard-De Hoop method in the half space SH problem.

将该方法和Cagniard De Hoop解析法在求解半无限空间地震波动的问题中进行比较，结果表明，新微分法的精度和解析方法的精度相同。

The validity of staggered grid real value FFT differentiation operator is confir med by comparing with the analytic CagniardDe Hoop method in the half space SH problem.

将该方法和CagniardDe Hoop解析法在求解半无限空间地震波动的问题中进行比较，结果表明，新微分法的精度和解析方法的精度相同。

According to the demand of high magnetic field power supply, reference is increased with a set ramp rate and stops at a set stable value, so reference system is composed of digital setting and digit to analog converting circuit. But the stability of reference is mostly guaranteed by the performance of D/A circuit, so D/A circuit is particularly studied in reference system. The scheme of D/A circuit, the selection of DAC and its voltage reference, hardware anti-jamming design and PCB design are discussed in detail, and software of remote control and PLC are discussed in brief. Zero-flux DC current transformer well satisfies the demands of the high stability of Load current detection unit, so the principle of zero-flux DC current transformer is analyzed; in the mean time a project which detects the long term stability is designed. During 8 hours, analog signal which is detected with high precision digit multimeter is recorded in computer at 1HZ frequency by GPIB communication. The drift error source and related parameters are explained in the compare-amplify part. Detailed subtraction circuit is designed; also amplifier chip and periphery components are selected and verified according to the theory of error analysis.

根据强磁场电源的需求，参考源应按照软件设定的斜率逐渐上升到设定稳态值，则参考源系统应由数字给定和数模转换电路两大部分组成，而参考源的稳定度主要依靠完成数模转换功能的模拟电路的性能来保证，因此本文对参考源系统的研究以数模转换电路为重点，分别从电路方案的确定、数模转换芯片及其基准电压源的选取和验证、电路板硬件抗干扰和PCB设计几方面进行了论述，然后对数字给定部分的远控组态和PLC程序设计作了简要介绍；采用零磁通原理的直流电流转换器很好地满足了对负载电流检测单元高稳定度的需求，本文详细分析了零磁通检测的原理，并在选定此种类型电流转换器的基础上设计了一套检测长期稳定度的方案，8小时内以1秒为采样周期，通过计算机Labview程序和高精度数字电压表的GPIB通讯，将被高精度数字电压表数字化后的模拟信号采样值连续记录至计算机中；比较放大环节简要阐述了漂移产生的原因和相关参数指标，确定了具体的减法电路形式，并根据误差分析理论对运算放大器和外围元器件进行了选取和验证。

The dilatometer has an absolute sensitivity of 0.03 micron and a relative error of 0.3x10~(-6) in respect to samples having a length of 10 cm.

它的绝对测长精度为0.03微米，试样长为10厘米时相对测长精度为 0.3 ×10~(-6)。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。