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21.
22.
George M. Janini Gary M. Muschik Carol M. Hanlon 《Molecular Crystals and Liquid Crystals》2013,570(1-2):15-27
The synthesis, phase transition temperatures and thermodynamic data (enthalpies and entropies) are reported for the methoxy through n-octyloxy (and n-decyloxy) homologues of the liquid crystal series represented by N,N′-bis[p-alkoxybenylidene]-α, aα′-bi-p-toluidine. The trends in transition temperatures are more or less analogous to previously-studied liquid crystal series. Nematic-isotropic enthalpy values are appreciably higher than average values for other series. Entropy values show the usual odd-even effect, but in contrast to observed trend for other series, they decrease with increasing terminal substituent chain length. Di-Schiff' s bases with various terminal substituents that showed interesting linear correlation between nematicisotropic transition temperatures and the anisotropy of polarizability of the substituent were also synthesized. A simple gas-liquid chromatographic method for the investigation of the selectivity of nematic stationary phases and its dependence on the degree of molecular order in the nematic state is also presented. 相似文献
23.
Corinne Hanlon Shaun Frape Rhys Gwynne 《Isotopes in environmental and health studies》2017,53(5):446-465
This study provides the first characterization of the variability of bromine and chlorine stable isotopic composition in evaporites, associated residual brines, and shoreline gases in terrestrial evaporative saline lakes. The lakes investigated here are groundwater discharge locations, and include both potash-rich alkaline lakes and sodic-dominated neutral pH lakes at a variety of salinities and evaporative stages. The chlorine and bromine isotope systems behave consistently different during evaporative salt precipitation, with 37Cl more enriched in the salt than in the fluid, but 81Br more enriched in the fluid compared with the precipitated salt. The 81Br concentration of shore off-gassing was even smaller than mineral precipitate compositions. The trends observed for bromine isotopes are surprising compared with published laboratory studies, indicating that a process besides inorganic mineral precipitation is affecting δ81Br. Additional processes explored include diffusion, salt deflation, microbial and photolytic conversion to the gas phase, and oxidative bromination of organic matter.
Dedicated to Professor Peter Fritz on the occasion of his 80th birthday 相似文献
24.
A new antibiotic, pseudomonic acid C (2a), has been isolated from fermentations of the strain of which produces the known and structurally similar antibiotics pseudomonic acids A (1a) and B (1c). 相似文献
25.
Phil Hanlon 《Journal of Graph Theory》1979,3(3):295-299
The degree sequence (d0, d1, …, dp-1) of a graph G of order p is defined by dk = the number of points of G of degree k. Methods of Robinson are extended to produce a generating function F(x0, x1, x2, …) where the coefficient of x…x is the number of graphs of order p having degree sequence (d0, …, dp-1). 相似文献
26.
27.
In this paper we study the Betti numbers of a type of simplicial complex known as a chessboard complex. We obtain a formula for their Betti numbers as a sum of terms involving partitions. This formula allows us to determine which is the first nonvanishing Betti number (aside from the 0-th Betti number). We can therefore settle certain cases of a conjecture of Björner, Lovász, Vreica, and ivaljevi in [2]. Our formula also shows that all eigenvalues of the Laplacians of the simplicial complexes are integers, and it gives a formula (involving partitions) for the multiplicities of the eigenvalues. 相似文献
28.
Numerous studies by molecular biologists concern the relationships between several long DNA sequences, which are listed in rows with some gaps inserted and with similar positions aligned vertically. This motivates our interest in estimating the number of possible arrangements of such sequences. We say that ak sequence alignment of sizen is obtained by inserting some (or no) 0's intok sequences ofn 1's so that every sequence has the same length and so that there is no position which is 0 in allk sequences. We show by a combinatorial argument that for any fixedk1, the numberf(k, n) ofk alignments of lengthn grows like (c
k
)
n
as n , wherec
k
= (21/k
– 1)
-k
. A multi-dimensional saddle-point method is used to give a more precise estimate forf(k, n).
Research supported in part by the National Science FoundationResearch supported in part by the System Development FoundationResearch supported in part by the National Institute of Health 相似文献
29.
Adams MR Aïd S Anthony PL Baker MD Bartlett J Bhatti AA Braun HM Busza W Conrad JM Coutrakon G Davisson R Derado I Dhawan SK Dougherty W Dreyer T Dziunikowska K Eckardt V Ecker U Erdmann M Eskreys A Figiel J Gebauer HJ Geesaman DF Gilman R Green MC Haas J Halliwell C Hanlon J Hantke D Hughes VW Jackson HE Jaffe DE Jancso G Jansen DM Kaufman S Kennedy RD Kirk T Kobrak HG Krzywdzinski S Kunori S Lord JJ Lubatti HJ McLeod D Magill S Malecki P Manz A Melanson H Michael DG Mohr W Montgomery HE 《Physical review D: Particles and fields》1993,48(11):5057-5066
30.
Ferm M Watt J O'Hanlon S De Santis F Varotsos C 《Analytical and bioanalytical chemistry》2006,384(6):1320-1330
A new passive particle collector (inert surrogate surface) that collects particles from all directions has been developed.
It was used to measure particle deposition at 35 test sites as part of a project that examined corrosion of materials in order
that variation in particulate material could be used in development of dose–response functions in a modern multi-pollutant
environment. The project, MULTI-ASSESS, was funded by the EU to examine the effects of air pollution on cultural heritage.
Passive samplers were mounted rain-protected, and both in wind-protected and wind-exposed positions, to match the exposure
of the samples for corrosion studies. The particle mass and its chemical content (nitrate, ammonium, sulfate, calcium, sodium,
chloride, magnesium and potassium) were analysed. The loss of light reflectance on the surrogate surface was also measured.
Very little ammonium and potassium was found, and one or more anions are missing in the ion balance. There were many strong
correlations between the analysed species. The mass of analysed water-soluble ions was fairly constant at 24% of the total
mass. The particle mass deposited to the samplers in the wind-protected position was about 25% of the particles deposited
to an openly exposed sampler. The Cl−/Na+ ratios indicate a reaction between HNO3 and NaCl. The deposited nitrate flux corresponds to the missing chloride. The Ca2+ deposition equals the deposition and the anion deficiency. The deposition most likely originates from SO2 that has reacted with basic calcium-containing particles either before or after they were deposited. The particle depositions
at the urban sites were much higher than in nearby rural sites. The deposited mass correlated surprisingly well with the PM10 concentration, except at sites very close to traffic. 相似文献