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31.
Gregory B. Kharas Xue Tian Whitney K. Castle Marie B. Cuison Maria R. Fath Bridget Nord 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(4):355-358
Electrophilic trisubstituted ethylene monomers, ring‐substituted 2‐cyano‐N,N‐dimethyl‐3‐phenyl‐2‐propenamides, RC6H4CH?C(CN)CON(CH3)2 (where R is 4‐(CH3)2N, 4‐CH3CO2, 4‐CH3CONH, 2‐CN, 3‐CN, 4‐CN, 4‐(C2H5)2N) were synthesized by potassium hydroxide catalyzed Knoevenagel condensation of ring‐substituted benzaldehydes and N,N‐dimethyl cyanoacetamide, and characterized by CHN elemental analysis, IR, 1H‐ and 13C‐NMR. Novel copolymers of the ethylenes and styrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator, ABCN at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C NMR, GPC, DSC, and TGA. High Tg of the copolymers in comparison with that of polystyrene indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. The gravimetric analysis indicated that the copolymers decompose in the 300–450°C range. 相似文献
32.
James E. Castle 《Surface and interface analysis : SIA》2022,54(4):455-464
The Auger parameter (AP) is a value extracted from the X-ray photoelectron spectrum (XPS) by addition of the binding energy of a photoelectron, for a given element in the spectrum, to the kinetic energy of the Auger electron emitted as the resulting hole in the electronic structure is filled by an electron from one of the outer orbitals. The value of the AP is sensitive to the polarization of electrons in the orbitals of neighbouring ions towards the photo-ionized atom and is thus related to other opto-electronic properties of the material. A correlation had been shown between the refractive index and the AP of aluminosilicates and thus the ability to compare, on a single chart, the AP's of the Al and Si ions gave important structural information. This comparison was made possible by normalising the individual APs to a common zero-point. In this contribution, the methodology employed is extended to a wider range of elements. The resulting ability, to compare and contrast the normalised AP, thus generated, greatly enhances the information available from XPS and thus relates it directly to the polarizability of the material's structure. 相似文献
33.
34.
A fast screening method consisting of off-line solid-phase microextraction coupled to HPLC and fluorescence detection, suitable for the analysis of several bisphenol derivatives and their degradation products in aqueous solution, has been developed. Detection limits of 0.7 ng ml(-1) for 2,2-bis[4-(glycidyloxy)phenyl]propane, 0.9 ng ml(-1) for bisphenol A bis(3-chloro-2-hydroxypropyl)ether, 1.1 ng ml(-1) for 2,2-bis(4-hydroxyphenyl)propane and 2.4 ng ml(-1) for bisphenol F diglycidyl ether have been achieved working in the linear range 10-500 ng ml(-1). The good analytical features achieved make the proposed method an interesting option for the direct determination of these compounds in aqueous canned food such as peas, tuna, olives, maize, artichokes or palm hearts. Both the optimization process and the results, including the analysis of real samples, are given and discussed. 相似文献
35.
A facile method for the preparation of the aromatic pyrrolo[1,5-b:2,3-c']dipyridazine ring system is reported. A number of compounds have been prepared and the biological screening data reported. 相似文献
36.
Abusaidi R Akerib DS Barnes PD Bauer DA Bolozdynya A Brink PL Bunker R Cabrera B Caldwell DO Castle JP Clarke RM Colling P Crisler MB Cummings A Da Silva A Davies AK Dixon R Dougherty BL Driscoll D Eichblatt S Emes J Gaitskell RJ Golwala SR Hale D Haller EE Hellmig J Huber ME Irwin KD Jochum J Lipschultz FP Lu A Mandic V Martinis JM Nam SW Nelson H Neuhauser B Penn MJ Perera TA Perillo Isaac MC Pritychenko B Ross RR Saab T Sadoulet B Schnee RW Seitz DN Shestople P Shutt T Smith A Smith GW 《Physical review letters》2000,84(25):5699-5703
The Cryogenic Dark Matter Search (CDMS) employs Ge and Si detectors to search for weakly interacting massive particles (WIMPs) via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. CDMS data, accounting for the neutron background, give limits on the spin-independent WIMP-nucleon elastic-scattering cross section that exclude unexplored parameter space above 10 GeV/c2 WIMP mass and, at >75% C.L., the entire 3sigma allowed region for the WIMP signal reported by the DAMA experiment. 相似文献
37.
Yovchev I.G. Lawson W.G. Nusinovich G.S. Granatstein V.L. Castle M. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2000,28(3):523-528
A design of a Ku-band 17.1-GHz four-cavity coaxial gyroklystron amplifier for driving future linear colliders is presented. The X-band input cavity operates in the TE0.11 mode, whereas the remaining three cavities (buncher, penultimate, and output) operate in the TE021 mode, doubling the frequency of the input signal. The electron beam parameters are the following: current of 540 A, voltage of 460 kV, perpendicular-to-parallel velocity ratio of 1.5, and a parallel velocity spread of 6.4%. The output cavity has been simulated as (1) zero-drive unstable with Q-factor of 320 and (2) zero-drive stable with Q-factor of 250. The simulations show that the maximum efficiency in the first case is 37.4%, and in the second one is 34.4%. In both cases, a high gain of 60 dB at a 100-MW output power level can be realized 相似文献
38.
Michael J. Quast Gary E. Martin Vincent M. Lynch Stanley H. Simonsen John G. Stuart Marvin L. Tedjamulia Raymond N. Castle Milton L. Lee 《Journal of heterocyclic chemistry》1986,23(4):1115-1118
The crystal structure of 9-methylphenanthro[4,3-a]dibenzothiophene, C25H16S, Mr = 348.47, has been determined. Monoclinic, P21/c, a = 11.364(3), b, = 14.257(3), c = 11.575(2)Å, β = 116.26(2)°, V = 1681.9(7)Å3, Z = 4, Dx = 1.38 g/cc, MoKα radiation λ = .71069 Å, F(000) = 728, T = 163K, R = .0458 for 2330 reflections. The structure compares favorably with that of hexahelicene and methylated derivatives. The thiophene moiety increases the helical core radius and decreases the pitch with respect to hexahelicene and its derivatives. 相似文献
39.
John P. Shockcor Ronald C. Crouch Gary E. Martin Abdallah Cherif Jiann-Kuan Luo Raymond N. Castle 《Journal of heterocyclic chemistry》1990,27(2):455-458
One-dimensional ( 1D ) variants of two-dimensional ( 2D ) nmr techniques can frequently provide the required information in a much shorter period of time than the 2D experiment from which they were derived. Application of the 1D homonuclear Hartmann-Hahn (1D-HOHAHA) experiment to establish proton-proton connectivity networks in highly overlapped four-spin systems in the proton nmr spectra of polynuclear aromatics is described. Selective subspectra are contrasted to the data obtained in a COSY experiment on the same molecule, benzo[f][l]benzothieno [2,3 -c]quinoline. Results from the 1D-HOHAHA technique are especially useful when component resonances from several spin systems are heavily overlapped. Relayed 1D-HOHAHA provides the means of exploiting small, long range coupling pathways of polynuclear aromatics. 相似文献
40.
Andrew S. Zektzer John G. Stuart Gary E. Martin Raymond N. Castle 《Journal of heterocyclic chemistry》1986,23(5):1587-1593
Phenanthro[3′,4′:3,4]phenanthro[2,1-b]thiophene has been prepared and its highly congested proton and carbon nmr spectra assigned. The nmr assignments required concerted utilization of two-dimensional nmr techniques which included: COSY, direct and long range optimized heteronuclear chemical shift correlation and heteronuclear relayed coherence transfer. 相似文献