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11.
Duffy DJ Quenneville J Baumbaugh TM Kitchener SA McCormick RK Dormady CN Croce TA Navabi A Stidham HD Hsu SL Guirgis GA Deng S Durig JR 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(3):659-671
Ab initio calculations are reported for three of four possible conformers of 1,3-dichloropropane. The fourth conformer, with Cs symmetry, has a predicted enthalpy difference of more than 1500 cm(-1) from the most stable conformer from each calculation regardless of the basis set used, so there is little chance of observing it. Thus, there is no evidence in the infrared or Raman spectrum of the presence of a fourth conformer. The order of stability given by the ab initio calculations is C2(GG)>C1(AG)>C2v(AA)>Cs(GG'), where A indicates the anti form for one of the CH2Cl groups and G indicates the gauche conformation for the other CH2Cl group relative to the plane of the carbon atoms. Almost every band observed can be confidently assigned to one or another of the conformers. Many observed bands proved to be of a composite nature, with several nearly coincident vibrations of different conformers contributing to the band contour. Nonetheless, a complete assignment of fundamentals is possible for the most stable C2 conformer, and 5 of the fundamentals of the C2v conformer and 13 those of the C1 conformer can be confidently assigned. 相似文献
12.
Xi Yao Stuart S. Dunn Philseok Kim Meredith Duffy Jack Alvarenga Joanna Aizenberg 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(17):4507-4511
Omniphobic fluorogel elastomers were prepared by photocuring perfluorinated acrylates and a perfluoropolyether crosslinker. By tuning either the chemical composition or the temperature that control the crystallinity of the resulting polymer chains, a broad range of optical and mechanical properties of the fluorogel can be achieved. After infusing with fluorinated lubricants, the fluorogels showed excellent resistance to wetting by various liquids and anti‐biofouling behavior, while maintaining cytocompatiblity. 相似文献
13.
Nanotextured multicrystalline Al‐BSF solar cells reaching 18% conversion efficiency using industrially viable solar cell processes
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Bishal Kafle Abdul Mannan Timo Freund Laurent Clochard Edward Duffy Marc Hofmann Jochen Rentsch Ralf Preu 《固体物理学:研究快报》2015,9(8):448-452
We report recent achievements in adapting industrially used solar cell processes on nanotextured surfaces. Nanostructures were etched into c‐Si surfaces by dry exothermic plasma‐less reaction of F species with Si in atmospheric pressure conditions and then modified using a short post‐etching process. Nanotextured multicrystalline wafers are used to prepare Al‐BSF solar cells using industrially feasible solar cell proc‐ essing steps. In comparison to the reference acidic textured solar cells, the nanostructured cells showed gain in short circuit current (Jsc) of up to 0.8 mA/cm2 and absolute gain in conversion efficiency of up to 0.3%. The best nanotextured solar cell was independently certified to reach the conversion efficiency of 18.0%. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
14.
Reversible addition–fragmentation chain transfer polymerization of alkyl‐2‐cyanoacrylates: An assessment of livingness
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Cormac Duffy Marisa Phelan Per B. Zetterlund Fawaz Aldabbagh 《Journal of polymer science. Part A, Polymer chemistry》2017,55(8):1397-1408
Alkyl 2‐cyanoacrylates (CAs) are primarily used as instant adhesives, including those sold under the Loctite brand. The adhesive action can be inhibited with acid stabilizers allowing radical polymerization to be employed. The following article details the first attempted controlled/living radical polymerization of alkyl CAs: Reversible addition fragmentation chain transfer (RAFT) polymerization mediated by a poly(methyl methacrylate) dithiobenzoate macroRAFT agent for three different CA monomers (ethyl 2‐cyanoacrylate, n‐butyl 2‐cyanoacrylate, and 2‐phenylethyl cyanoacrylate) allowed the preparation of the first block copolymers of this challenging but commercially important monomer class. Nevertheless, GPC with UV detection indicated significant loss of the RAFT end‐group for all three CAs limiting control/living character. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 1397–1408 相似文献
15.
This paper reports the computer generation of atomic models for amorphous tetrahedrally coordinated materials. Several approaches are used and their results are intercompared in terms of careful statistical studies on each structure. The best approach is capable of automatically building large models with no included voids or dangling bonds. The strain energies are minimized for each structure implying that they represent metastable equilibrium arrangements; the radial distribution functions are in excellent agreement with experimental data. The programs developed are capable of building models which vary systematically as measured by several parameters including the ratio of five to six membered rings and the average distortion of the tetrahedra formed by near neighbors. 相似文献
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18.
Bobby G. Poe III Ciarán F. Duffy Michael A. Greminger Bradley J. Nelson Edgar A. Arriaga 《Analytical and bioanalytical chemistry》2010,397(8):3397-3407
Mitochondrial DNA (mtDNA) mutations have been associated with disease and aging. Since each cell has thousands of mtDNA copies,
clustered into nucleoids of five to ten mtDNA molecules each, determining the effects of a given mtDNA mutation and their
connection with disease phenotype is not straightforward. It has been postulated that heteroplasmy (coexistence of mutated
and wild-type DNA) follows simple probability rules dictated by the random distribution of mtDNA molecules at the nucleoid
level. This model has been used to explain how mutation levels correlate with the onset of disease phenotype and loss of cellular
function. Nonetheless, experimental evidence of heteroplasmy at the nucleoid level is scarce. Here, we report a new method
to determine heteroplasmy of individual mitochondrial particles containing one or more nucleoids. The method uses capillary
cytometry with laser-induced fluorescence detection to detect individual mitochondrial particles stained with PicoGreen, which
makes it possible to quantify the mtDNA copy number of each particle. After detection, one or more particles are collected
into polymerase chain reaction (PCR) wells and then subjected to real-time multiplexed PCR amplification. This PCR strategy
is suitable to obtain the relative abundance of mutated and wild-type mtDNA. The results obtained here indicate that individual
mitochondrial particles and nucleoids contained within these particles are not heteroplasmic. The results presented here suggest
that current models of mtDNA segregation and distribution (i.e., heteroplasmic nucleoids) need further consideration. 相似文献
19.
E. R. Dixon M. S. A. Blackwell M. S. Dhanoa Z. Berryman N. de la Fuente Martinez D. Junquera A. Martinez P. J. Murray H. F. Kemp W. Meier‐Augenstein A. Duffy R. Bol 《Rapid communications in mass spectrometry : RCM》2010,24(5):511-518
Variations in natural abundance of carbon (C) and nitrogen (N) stable isotopes are widely used as tools for many aspects of scientific research. By examining variations in the ratios of heavy to light stable isotopes, information can be obtained as to what physical, chemical and biological processes may be occurring. The spatial heterogeneity of soil δ15N‐ and δ13C‐values across a range of scales and under different land use have been described by a number of researchers and the natural abundances of the C and N stable isotopes in soils have been found to be correlated with many factors including hydrology, topography, land use, vegetation cover and climate. In this study the Latin square sampling +1 (LSS+1) sampling method was compared with a simple grid sampling approach for δ13C and δ15N measurement at the field scale. A set of 144 samples was collected and analysed for δ15N and δ13C from a 12 × 12 grid (in a 1 ha improved grassland field in south‐west England). The dimension of each cell of the grid was approximately 11 × 6 m. The 12 × 12 grid was divided into four 6 × 6 grids and the LSS+1 sampling technique was applied to these and the main 12 × 12 grid for a comparison of sample means and variation. The LSS+1 means from the 12 × 12 grid and the four 6 × 6 grids compared well with the overall grid mean because of the low variation within the field. The LSS+1 strategy (13 samples) generated representative samples from the 12 × 12 grid, and hence would be an acceptable method for sampling similar plots for the measurement of mean isotopic composition. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
20.
We consider a single-server first-in-first-out queue fed by a finite number of distinct sources of jobs. For a large class
of short-range dependent and light-tailed distributed job processes, using functional large deviation techniques we prove
a large deviation principle and logarithmic asymptotics for the joint waiting time and queue lengths distribution. We identify
the paths that are most likely to lead to the rare events of large waiting times and long queue lengths. A number of examples
are presented to illustrate salient features of the results.
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