The design of a pulsed field gradient unit for USES on NMR spectrometers is discussed.
给出一种用于核磁共振谱仪的脉冲场梯度单元的详细设计。
Results: Making use of the low field gradient echo (GE) -t2w's scanning can improve identifying meniscus injury.
结果应用低场梯度回波序列(GE)T2 W扫描可提高半月板损伤的诊断。
Then the magnetic field gradient of these magnetic field profiles was obtained quantitatively using Lorentz fit.
用洛伦兹拟合定量地得到了三种磁场形貌的磁场梯度。
The more smaller pore size, the more stronger internal Magnetic field gradient. The nmr porosity is significantly lower.
岩石孔径越小，岩石孔隙内部磁场梯度越强，核磁共振测井计算的孔隙度明显偏低；
Current must change working gap size can make the magnetic field strength and magnetic field gradient simultaneous changes.
电流一定时，改变工作间隙的大小可以使磁场强度和磁场梯度同时发生变化。
Approximate theoretical expressions are given for dipole moment, field gradient at the nucleus, and nonlinear susceptibility of crystals.
建立了偶极矩、核四极矩偶合常数中的场梯度及晶体非线性光学系数的近似理论表达式。
The electric current passing through the conductor on the film of bubble generates a local magnetic field gradient to make the bubble propagate.
国际地磁参考场与局部地磁场模型的研究，具有深远的学科意义与巨大的实用价值。
A magnetic resonance imaging scanner (10) includes a main magnet (12), magnetic field gradient coils (16), and one or more radio frequency coils (18).
一种磁共振扫描器(10)包括主磁体(12)、磁场梯度线圈(16)和一个或多个射频线圈(18)。
Igneous rock with strong magnetic susceptibility, leading to strong internal magnetic field gradient, and to T2 spectrum forward and NMR porosity decrease.
火成岩具有强磁化率，导致火成岩孔隙内部产生强磁场梯度，使火成岩的核磁测井T2谱发生前移、核磁孔隙度减小；
We researched the effects of sucrose on the spin- spin relaxation property in dough using pulsed field gradient Nuclear Magnetic Resonance ( PFG- NMR) techniques.
利用脉冲梯度场核磁共振技术（PFG-NMR）研究蔗糖对面团自旋-自旋弛豫特性的影响。
A general method for designing magnetic field gradient coils on a cylindrical surface with an axial magnetic field to be used in NMR imaging is suggested and developed.
系统地介绍了用于磁共振成像系统中具有轴向磁场的圆柱型表面梯度线圈的设计与优化。
The magnetic field gradient is surveyed again at 199 sites in Urumqi geomagnetic station using high sensitivity nuclear procession magnetometers of Type G856 and DTZ 2.
使用高灵敏度的G856、dtz2型核子旋进式磁力仪，对乌鲁木齐地磁台199个测点的磁场梯度进行了复测。
The phase mapping method of a field inhomogeneity based on an Z axis pulse field gradient and polynomial fitting procedures of the axial shimming coil currents were described.
通过对Z轴磁场梯度和匀场线圈电流的多项式拟合，以获得磁场不均匀而引起的相位分布。
Using the strong background magnetic field produced by effective electromagnet and the catching surface to produce high magnetic field gradient makes the separation of micro-grade material possible.
利用有效电磁体产生的强背景磁场和能产生高磁场梯度的捕集表面，使得分选微米级的物料成为可能。
Well, we've seen this criterion that if a curl of the vector field is zero and it's defined in the entire plane, then the vector field is conservative, and it's a gradient field.
我们已经知道了一个准则，如果向量场的旋度为零，而且它在整个平面上有定义，那么这个向量场是保守的，而且它是个梯度场。
If you fail this test then you know for sure that you are not gradient field so you might as well do that.
如果通不过检验，那么可以肯定，它不是梯度场，你可能也会那样做。
So, if the gradient of a function is a vector, the divergence of a vector field is a function.
如果说函数的梯度是向量，那么向量场的散度就是函数。
If we have a vector field that cannot possibly be a gradient then we shouldn't try to look for a potential.
如果一个向量场不可能是梯度场，那我们就不应该尝试去找势函数。
And it is a gradient field in that part of the plane and conservative and so on. The answer for now is, in general, no.
在那部分平面上，梯度场，是保守的，目前来说结论一般是不对的。
Well, if I have a gradient field, then if I try to compute this line integral, I know it will be the value of the function at the end point minus the value at the starting point.
如果有一个梯度场，然后想计算线积分，我知道积分值是,起点的函数值减去终点的函数值。
OK, so that's the general method of calculation, but we've seen a shortcut for work when we can show that the field is the gradient of potential.
这就是计算的一般方法，但求功的时候，如果向量场是某个势的梯度,是有捷径可走的。
Well, actually here it is not very hard to find a function whose gradient is this vector field.
实际上，找出一个函数，其梯度是这个向量场并不难。
Well, if we know that it's a gradient field, that we've seen that we get these properties out of the fundamental theorem.
如果我们知道它是一个梯度场，就可以由基本定理，得到上面那些性质。
So, if you have a gradient field, it's what's called conservative.
如果有一个梯度场，它也是一个保守场。
OK, so, we've seen that if we have a vector field defined in a simply connected region, and its curl is zero, then it's a gradient field, and the line integral is path independent.
一个向量场,如果定义在单连通区域并且旋度为零，那么它就是一个梯度场，并且其上的线积分与路径无关。
One is to say that the vector field is a gradient in a certain region of a plane.
一个是向量场,在给定平面区域内是梯度场。
So, actually on Tuesday we'll see how to decide whether a vector field is a gradient or not, and if it is a gradient, how to find the potential function.
周二我们就知道，怎样确定一个场是不是梯度，如果确实是梯度的话，怎样算出势函数。
Ok, so just to reinforce my warning that not every field is a gradient field, let's look again at our favorite vector field from yesterday.
好的，为了强调，不是所有场都是梯度场，我们再来看看昨天那个向量场。
The test that we saw last time saying, well, to check if something is a gradient field if it's conservative, 0 we just have to compute the curl and check whether it's zero.
由上次的测试可知，如果一个东西是保守的，要确定是不是梯度，我们只需要计算旋度，查看它是否是。
The test that we saw last time saying, well, to check if something is a gradient field if it's conservative, 0 we just have to compute the curl and check whether it's zero.
由上次的测试可知，如果一个东西是保守的，要确定是不是梯度，我们只需要计算旋度，查看它是否是。
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