We report the negative ion photoelectron spectra of (NH3)n541– 1100 2 , recorded using 2.540 eV photons. The largest cluster anion in this series has a diameter of approximately 4.3 nm. The vertical detachment energies ~VDEs! of these cluster anions increase smoothly from 0.55 eV for n541 to 1.05 eV for n51100. The VDEs throughout this size range are linear with n and extrapolate to a VDE (n5`)...

OBJECTIVE To formulate cytologic features for differential diagnosis of basal cell adenoma (BCA). STUDY DESIGN The usefulness of 5 items for a cytologically definitive diagnosis of BCA was examined. The 5 items in 8 BCA and 22 non-BCA cases (adenoid cystic carcinoma [ADCC], basal cell adenocarcinoma, myoepithelioma, pleomorphic adenoma and polymorphous low-grade adenocarcinoma) that displayed...

Finding a data clustering in a data set is a challenging task since algorithms usually depend on the adopted inter-cluster distance as well as the employed definition of cluster diameter. The work described in this paper approaches a well-known agglomerative clustering algorithm named AGNES (Agglomerative Nesting), in regards to its performance on three case studies namely, datasets formed by c...

We review two clustering algorithms (hard c-means and single linkage) and three indexes of crisp cluster validity (Hubert's statistics, the Davies-Bouldin index, and Dunn's index). We illustrate two deficiencies of Dunn's index which make it overly sensitive to noisy clusters and propose several generalizations of it that are not as brittle to outliers in the clusters. Our numerical examples sh...

Abstract. Atmospheric new particle formation (NPF) events are regularly observed in urban Beijing, despite high concentrations of background particles which, based on theory, should inhibit NPF due to values coagulation sink (CoagS). The survival probability, which depends both CoagS and growth rate (GR), is a key parameter determining the occurrence as it describes fraction newly formed that s...

During analysis of the relation of quasars to galaxies in the 2dF deep field a concentration of quasars was noted. Most striking was the closeness in redshift of 14 quasars about the mean redshift z = 2.149 with a range of ±.018. The cluster in spite of its high redshift subtends an area of diameter more than 2.3 degrees on the sky. At conventional redshift distance its diameter would be 181 me...

The role of the ionomer architecture in the formation of ordered structures in poled membranes is investigated by molecular dynamics computer simulations. It is shown that the length of the sidechain L(s) controls both the areal density of cylindrical aggregates N(c) and the diameter of these cylinders in the poled membrane. The backbone segment length L(b) tunes the average diameter D(s) of cy...

Clustering is a process of discovering groups of objects such that the objects of the same group are similar, and objects belonging to different groups are dissimilar. A number of clustering algorithms exist that can solve the problem of clustering, but most of them are very sensitive to their input parameters. Therefore it is very important to evaluate the result of them. The minimum spanning ...

A theoretical treatment is given of the recently discovered thermotransport effect in pure liquid metals. The isotope effect is related to the diffusive mass flow by a proportionality factor familiar from electrotransport. The mass flow is given primarily by the temperature dependence of the mean size or amount of density fluctuations in the liquid. Very little activation energy is required for...

The chemical vapor deposition (CVD) method is the most common technique for production of single walled carbon nanotubes (SWNTs). During the CVD process, an SWNT grows from decomposed carbon atoms on a catalytic metal particle fed by molecules such as CO, CH4 or ethanol at high temperature. Therefore, understanding surface chemical reaction is critically important, however, little is known due ...