Partial exact searching

WebMolecules Web visualization of molecules in 3D - in real-time - has now been achieved. Over 150,000 molecular models are available onsite, which may be searched by CAS number or exact form ula. In addition partial formula searching is permitted to look into the Top 2,000 molecules, which includes molecules of commercial value, educational importance, and of topical interest. Thousands of common molecules are organized into over 30 categories. http //www.webmolecules.com... 

Poorly cleaned surfaces may not image well. While ordinary dry dust will be brushed aside by the tip and will not affect the image, oily or partially anchored dirt will deflect the SFM tip or interfere with the conductivity in STM. The result is usually a line smeared in the scan direction, exactly as one would expect if the tip began scanning something which moved as it was scanned. If the sample cannot be cleaned, the best procedure is to search for a clean area. 

Consider the basic probkun of how information is distributed throughout a system, and the manner in which it is retrieved. We. know that in a conventional computer, for example, information is stored in random-access memory (RAM). This means that the memory address of where the information actually exists and the information itself are uncorrelated. In order to retrieve the information, one must know its address exactly, as even the slightest error renders that information effectively unretrievable. In particular, it is in general impossible to retrieve RAM data if armed only with a partial knowledge of its address. In contrast, associative memories (sometimes also called content-addressable memories), much like the form of memory believed to be used by human brains, are such that they can be completely retrieved even when searched for with partial information,... 

The coincidence of a node match with a structure match can be evaluated in the original reduced graph. If a mismatch between nodes is identified then the candidate structure is rejected, otherwise the reduced graph is resolved, i.e., nodes representing alternative partial structures are resolved, and any structure matches which can be identified at this level are determined the remaining node pairs are then subjected to further steps of the refined search. The exact order of implementing these steps, and whether all steps are necessary, e.g., the comparison of RPVs as a step preceding the comparison of EPVs, has yet to be determined. 

Substructure searching involves the identification of all entities in a CIR system that contain a user-defined partial structure. The query identifies this partial structure exactly. Substructure searching will always identify structures which are equal in size or larger than the query. 

Fuzzy 2D substructure searching is an extension of substructure searching to the minor extent that it permits the expansion of the query formulation vocabulary to include topological features and substructural wildcards described above. This involves the retrieval of all entities in a CIR system that contain the user-defined partial structure and that satisfy whatever wildcard specification pattern has been specified. The query identifies the partial structure and simple wildcard substitution patterns exactly. As with substructure searching, the use of query features on a partial structure will always identify structures which are equal in size or larger than the query. 

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