电阻

Keywords well logging instrument;cased hole formation resistivity logging;apparent resistivity;error analysis;second order potential difference

测井仪器；过套管电阻率测井；视电阻率；误差分析；二阶电位差

The result shows that the mixed boundary condition can greatly reduce the calculation area without affecting accuracy of the solution.It is followed by the higher accuracy of Dirichlet boundary condition which makes the boundary error greater when measured points is near the boundary, so we must take a sufficiently large border region.The homogeneous boundary condition has relatively large error, but the use of non-triangle poles devices makes apparent resistivity calculation error become small, because of elimination of the effect on potential difference for the infinite boundary. In inversion, in order to save computing time, homogeneous boundary conditions are often used to perform finite element forward calculation.

结果表明，混合边界条件精度最高，可大大缩小求解区域而不影响计算精度，其次是Dirichlet边界条件精度较高，但测点越靠边界误差会越大，必须取足够大的边界区域，齐次边界条件的误差比较大，但如果采用非二极装置，通过电位差计算得到的视电阻率，由于无穷远边界对电位差的影响基本消除，视电阻率计算误差与混合边界条件下的接近，在反演中，为了节省计算时间，经常使用齐次边界条件进行有限元正演。

The equation of the large rectangular loop source cloud expresses induced electromotive force at any field points accurately, the apparent resistivity derived from that is not subject to edge effects; the observation is still made with central loop pattern and in near zone, and the simple and direct relationship between induced electromotive force and apparent resistivity could be maintained.

大定源回线公式可以准确地表示任意场点的感应电动势，由此导出视电阻率无边缘效应影响；观测按照中心回线方式并保持在近区进行，可使感应电动势和视电阻率之间的转换简单而直接。

Referring to related newly developed methods abroad,in the paper, the expressions of frequency domain apparent resistivity and its numerical calculating formulae of electromagnetic field of vertical magnetic dipole source for the surface of horizontally layered media have been obtained.

该文参考国外最新发展的方法，求取了水平层状介质表面上垂直磁偶极源电磁场的频域视电阻率表达式及其数值计算公式，并用自编程序计算了几种典型地电断面的视电阻率曲线，以说明这种方法的有效

Analysis suggests that errors are mainly caused by approximate computation and the value of contacted resistance adopted.

误差产生的主要原因是计算过程中的近似和短路片接触电阻的取值，其中短路片接触电阻是一个重要因素，在设计腔体时应引起足够的重视。

But the clean sand model through which we can calculate for- mation water resisitivity is unsuitable for argillaceous sandstone .

地层水电阻率是测井解释中一个极其重要的参数，以纯地层条件推导的用于确定地层水电阻率的自然电位理论模型不适合泥质砂岩地层。

Formation water resisitivity is one of the key parameters in log interpretation.But the clean sand model through which we can calculate for- mation water resisitivity is unsuitable for argillaceous sandstone.

地层水电阻率是测井解释中一个极其重要的参数，以纯地层条件推导的用于确定地层水电阻率的自然电位理论模型不适合泥质砂岩地层。

Research on rock mechanic characteristics of slight weather argillaceous sandstone s in Sichuan Basin;2. But the clean sand model through which we can calculate for- mation water resisitivity is unsuitable for argillaceous sandstone .

地层水电阻率是测井解释中一个极其重要的参数，以纯地层条件推导的用于确定地层水电阻率的自然电位理论模型不适合泥质砂岩地层。

In the respect of data interpretation proceeding, the paper carried out the inversion calculation of experiment data with the resistivity CT method, gave some study on the image effect when the iron bodies were placed flatly close to water level under semi-space condition and were placed flatly, vertically or aslope to the water level under whole-space condition.

在资料解释处理方面，本文采用了电阻率CT法对实验数据进行反演计算，研究了半空间和全空间条件下铁块水平、垂直和倾斜放置时的成像效果，由效果图可以看出，通过电阻率CT法反演出的铁块的位置与水槽模拟实验中铁块的实际位置吻合的较好。

This paper describes the principle of control system with binary coding starting resistance for long distance belt conv...

论述了长距离胶带机二进制编码起动电阻控制系统的原理以及在工程中的应用，并简要介绍了二进制编码电阻的计算方法。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。