Nodes 3-connecting metallic

Trace A node-to-node connection, which consists of one or more tracks. A track is a metal line on the PWB. It has a start point, an end point, a width, and a layer. 

We use the word connectivity to describe the number of nodes connected to each node. As connectivity is used in a dilTerent sense in graph theory coordination" is soinetimcs used instead. However, since this word is used in again another way in coordination chemistry (a metal ion may be a three connected node but still six-coordinated) we are left with a situation where someone is bound to be unhappy. 

This node(s) presents a different problem. Its AC voltage can be easily capac-itively coupled into any adjacent traces on different metal layers, as well as radiate EMI. Unfortunately, it is generally the trace that must also act as a heatsink for both the power switch and the rectifiers, especially in surface mount power supplies. Electrically, the trace wants to be as small as possible, but thermally, it wants to be large. There is one good compromise in the surface mount designs, and that is to make the top PCB island identical to the bottom PCB island and connect them with numerous vias (or thru-hole connections). This can be seen in Figure 3-62. 

Fig. 10 Simple circuit diagrams of the different series and parallel association of molecular wires Mi and M2 discussed in the text. The two molecular wires are (a) bonded in series, (b) connected in parallel on the metallic pads, (c) forming a single molecule with one intramolecular node, and (d) forming a single molecule with two intramolecular nodes...

The net conveniently referred to as the rutile net consists of 6-connecting, essentially octahedral nodes, each connected to twice as many 3-connecting, essentially trigonal nodes - this is an example of a 3,6-connected net. The series of isostruc-tural binary metal-tcm compounds, [M(tcm)2] (tcm- is the tricyanomethanide... 

One of the best studied families of porphyrins for use as metalloligands is comprised of metalated 7e50-tetra(p-carboxyphenyl)porphyrins (TCPPs). Several reviews have discussed the synthesis and properties of TCPP CPs and MOFs (38, 102, 103). As with other supramolecular structures, the structures of these TCPP MOFs are dictated by the geometries of their nodes. Typically, TCPP MOFs have two types of nodes the four-connected, approximately square-planar porphyrins, and the SBUs, which can have various geometries but... 

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