Existing Nd and Hf isotopic data allow either crustal growth with no recycling of crust to mantle, or a model of constant-mass continental crust with extensive recycling. This implies that all intermediate growth plus recycling combinations are also permitted....
y= nanmean(X,vecdim)returns the mean over the dimensions specified in the vectorvecdim. The function computes the means after removingNaNvalues. For example, ifXis a matrix, thennanmean(X,[1 2])is the mean of all non-NaNelements ofXbecause every element of a matrix is contained in the...
The mean free time 7 of copper is approximately constant, and in particular does not depend on any electric field that might be applied to a sample of the copper. Thus. we need not consider any particular value of applied electric field. However, because the resistivity p displayed by copper...
【题目】The hurmonic mean o f x and the constant A is given by{$$ f ( x ) = 0 . 5 ( x ^ { - 1 } + A ^ { - 1 } ) ^ { - } $$1. Find a formul a for f*1}(x). 相关知识点: 试题来源: 解析 【解析】 $$ f ^ { - 1 } ( x ) = ( 0 . 5 x ^ { - ...
“These changes are like a tune-up for the email world, and by fixing a few things under the hood, we can keep email running smoothly. But just like a tune-up, this is not a one-time exercise. Keeping email more secure, user friendly and spam-free requires constant collaboration and ...
The root-mean-square or rms value of a time-varying quantity is that which delivers the same amount of power on average as a constant quantity of the same value. For example, a direct electrical current passing through an electrical resistance produces the same amount of heat as an alternatin...
What do you mean by catalyst? What is the effect of catalyst on the rate constant of reaction? 相关知识点: 试题来源: 解析 Catalyst increases rate of reaction by lowering down the activation energy rate of reaction increases by using the catalyst.1 ...
The main idea of the algorithm is to learn a metric matrix so that the distance between similar pairs of samples is small and the distance between dissimilar pairs of samples is large. The algorithm can make the distribution of similar pairs of samples more compact in the new metric space, ...
Thus, the area under the pressure–time trace is equal to the area of a box one cycle long with a constant pressure of PA. The relationship between the pressure trace and PA is shown in Figure 5.9.3. The mean arterial pressure can be approximated by a rule-of-thumb calculation: [5.9....
However, scientists have found that the temperature is not constant and our planet is actually getting 6. ( warm ) each year. This is called “global warming” and it is a major part of climate change. Extreme changes in climate are nothing new on Earth. In 7. ( it ) long history, ...