下延

The method of apparent density mapping in frequency domain is very quick.

视密度反演的频率域方法具有速度快的特点，但由于其关键运算向下延拓算子的不稳定，造成该方法精度不能达到实际应用的要求。

Integral iteration method is a kind of stable downward continuation method for potential fields.

积分-迭代法是一种解决位场大深度向下延拓的实用方法。

In this paper, taking the downward continuation of potential field as an inverse problem of upward continuation, we obtain a convolution type linear integral equation for downward continuation. Making use of the orthogonal symmetry characteristic of Fourier transform matrix, and combining the principles of singular value decomposition of matrix and generalized inverse, we proposed a stable generalized inverse method for downward continuation of potential field, called wavenumber domain generalized inverse algorithm, which doesn't need the computation for inverse matrix. It resolves the instability of potential field downward continuation of large depth.

本文通过把位场向下延拓视为向上延拓的反问题，得到向下延拓的褶积型线性积分方程，再利用Fourier变换矩阵的正交对称特性，并结合矩阵的奇异值分解和广义逆原理，提出了一种稳定的不需要进行求逆运算的位场向下延拓广义逆方法——波数域广义逆算法，解决了位场大深度向下延拓的不稳定性问题。

Once you have 一旦你 download Startup Delayer 下载启动延时, installed and configured the delayed time for each application, don't forget to press the " Activate " button! You can see Startup Delayer in action in the next Windows startup process by choosing a " Graphical Version " or choose an " Invisible Version " to let it works its wonders in the background.

安装和配置的延迟时间，为每个申请时，不要忘了按下"启动"按钮，你可以看到启动延时在行动，并在未来的Windows启动过程中，选择了"图文版"，或选择"隐形版"让它工程，它创造奇迹的背景。

In this paper, an iterative approach to potential field continuation from curved surface to plane is proposed. The continuation of potential field data from a curved surface to a plane can be viewed as an inverse problem of upward continuation of plane potential field data, getting a linear integral equation. Through viewing the potential field data on the curved surface as the data on the average elevation plane of the curved surface, then using the wavenumber domain generalized inverse algorithm to downward continue the data from the average elevation plane to a given plane, and a topography correction based on the change of curved surface relative to its average elevation is implemented to the downward continued data on the given plane, finally the downward continued data plane is upward continued to the curved surface.

本文提出一种位场数据曲化平的迭代方法，即通过把位场数据曲化平视为平面位场数据向上延拓的反问题，得到曲化平的线性积分方程，再把曲面上位场数据视为曲面平均高程面上的位场数据，利用向下延拓的波数域广义逆算法把平均高程面上的位场数据向下延拓到设定平面上，再根据曲面和其平均高程面的相对起伏对设定平面上的向下延拓数据进行起伏校正，最后再把所得平面上的位场数据向上延拓得到曲面上的位场数据，并进行迭代。

Now if the pedal is depressed after the note is struck, there will be sympathetic vibration in octave and harmonic strings, but all the other strings will be almost totally quiet because the standing waves contain only pure harmonics.

钢琴不只选择性的让常态模式留在钢琴中，还会选择性的发出常态模式的音响。如果在弹下一个音之后再踩下延音踏板，此时就只有八度音及一些和弦音的弦会受到影响而震动，其它的弦几乎都不会受到影响而保持静止状态。

Basal leaves basally decurrent along petiole, forming wings or slightly decurrent.

沿着叶柄下延的基部的基生叶，形成翅或稍下延。

This paper presents a rapid inversion method for 3D apparent density based on separation and continuation of potential field. The new method is carried out in the following three steps. Firstly, the gravity field on the plane is separated by a cutting method into several parts corresponding to strata of different depth. Secondly, by the way of downward continuation, the field resulted from different strata is respectively reduced to a plane corresponding to its depth.

文中提出了一种基于位场分离与延拓的视密度快速反演方法：首先应用场分离的切割法对平面上的重力场进行不同深度层源的切割分离；然后运用大深度向下延拓方法将各层的场延拓至相应的深度；最后反演出各深度层的密度。

If the pedal is depressed before a note is played, the initial time dependent traveling waves will excite all strings, creating a soft background roar.

如果我们在弹下一个音以前先踩下延音踏板，一开始的「泛音」会激发所有的弦，而产生一个嗡嗡声的音效。

The downward continuations are made by the iteration method and the FFT for a model and practical data, respectively. The effect of the iteration method is much better than the FFT.

本文用迭代法对模型数据和实际数据进行向下延拓，对比了迭代法与常规的FFT法在位场向下延拓中的效果，迭代法显著优于FFT法。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。