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31.
H. İBRAHİM UĞRAŞ ÜMİT ÇAKIR AKIN AZİZOĞLU TURGUT KILIÇ ÇAKIL ERK 《Journal of inclusion phenomena and macrocyclic chemistry》2006,55(1-2):159-165
Hexadecanoyl, dihexadecanoyl, dioctadecaneoyl, di-10-undecenoyl, and dicis-9-octadecenoyl derivatives of benzo[18]crown-6, dibenzo[18]crown-6 and dibenzo[24]-8 were synthesized by the condensation of carboxylic acids (palmitic, stearic, oleic and undecenoic acid) with benzo and dibenzo crown ethers in the presence of zinc chloride. The extraction equilibrium constants of such macrocyclic ethers with long side chains were estimated using chloroform/water and dichloromethane/water membranes transfer of Na-PAR (4-(2-pyridylazo)-resorcinol mono sodium monohydrate) with UV–Vis spectroscopy. It was found that they were in the range of 10.88–11.71 in dichloromethane and 8.04–11.77 in chloroform. These results actually show that the Na+ binding effect of macrocyclic ethers depends on the type and the length of side chains. The geometrical properties of the molecules were studied employing semi-empirical calculations by simulated annealing technique. The frontier molecular orbital energies and dipole moments were also examined. The biological activity results showed that the synthesized crown ethers have no activity against the studied microorganisms. 相似文献
32.
N. RAÏSSI 《Natural Resource Modeling》2001,14(2):287-310
ABSTRACT. After the extension of the Exclusive Economic Zone, in 1977, to 200 miles, most fish stocks came under jurisdiction of the adjacent coastal states. This development opened prospects of effective management of the open sea fisheries. Coastal states have the right to plan out the operation of so-called by Clarke and Munro “distant water fishing nations” from their Exclusive Economic Zone. Under some arrangements, a foreign fleet is allowed to harvest the resource in the Exclusive Economic Zone area. Clarke and Munro, in [1987] and [1991], focus on the issue of optimum terms and conditions of access and, in doing so, built a multiobjective model. The main goal of the present work is the development of a more general model including more variables and parameters related to the presence of a domestic fleet as well as a distant water fishing nation. The main difficulty resides in sharing the harvesting between the two fleets. The study responds to the realistic problemof coastal states who own enough resource stocks to allow harvesting by several kinds of fleets. Two optimal scenarios are developed, in each of them a solution is given. 相似文献
33.
Lu LC Burnstein RA Chakravorty A Chen YC Choong WS Clark K Dukes EC Durandet C Felix J Fu Y Gidal G Gustafson HR Holmstrom T Huang M James C Jenkins CM Jones TD Kaplan DM Longo MJ Luebke W Luk KB Nelson KS Park HK Perroud JP Rajaram D Rubin HA Volk J White CG White SL Zyla P;HyperCP Collaboration 《Physical review letters》2006,96(24):242001
The asymmetry in the rho angular distribution in the sequential decay Omega+-->LamdaKappa+-->rhopi+Kappa+. has been measured to be alphaOmegaalphaLamda=[+1.16+/-0.18(stat)+/-0.17(syst)]x10(-2) using 1.89x10(6) unpolarized Omega+ decays recorded by the HyperCP (E871) experiment at Fermilab. Using the known value of alphaLamda, and assuming that alphaLamda=-alphaLamda, alphaOmega=[-1.81+/-0.28(stat)+/-0.26(syst)]x10(-2). A comparison between this measurement of alphaOmegaalphaLamda and recent measurements of alphaOmegaalphaLamda made by HyperCP shows no evidence of a violation of CP symmetry. 相似文献
34.
T. Kitagaki S. Tanaka H. Yuta K. Abe K. Hasegawa A. Yamaguchi K. Tamai T. Hayashino S. Kunori Y. Ohtani H. Hayano R.A. Burnstein J. Hanlon H.A. Rubin C.Y. Chang T. Dombeck G.A. Snow D. Son J. Schneps 《Physics letters. [Part B]》1980,97(2):325-328
In an analysis of ≈ 7000 charged current events produced in high energy neutrino-deuterium interactions, we observe that the struck quark jet has a wider spread in Pt than that from the recoiling diquark jet for events with hadronic energy W > 9 GeV. This suggests that the effect signals the onset of gluon emission from the single quark. 相似文献
35.
Park HK Burnstein RA Chakravorty A Chen YC Choong WS Clark K Dukes EC Durandet C Felix J Fu Y Gidal G Gustafson HR Holmstrom T Huang M James C Jenkins CM Jones T Kaplan DM Lederman LM Leros N Longo MJ Lopez F Lu LC Luebke W Luk KB Nelson KS Perroud JP Rajaram D Rubin HA Volk J White CG White SL Zyla P;HyperCP Collaboration 《Physical review letters》2005,94(2):021801
We report the first evidence for the decay Sigma(+)-->pmu(+)mu(-) from data taken by the HyperCP (E871) experiment at Fermilab. Based on three observed events, the branching ratio is B(Sigma(+)-->pmu(+)mu(-))=[8.6(+6.6)(-5.4)(stat)+/-5.5(syst)]x10(-8). The narrow range of dimuon masses may indicate that the decay proceeds via a neutral intermediate state, Sigma(+)-->pP(0),P0-->mu(+)mu(-) with a P0 mass of 214.3+/-0.5 MeV/c(2) and branching ratio B(Sigma(+)-->pP(0),P0-->mu(+)mu(-))=[3.1(+2.4)(-1.9)(stat)+/-1.5(syst)]x10(-8). 相似文献
36.
Park HK Burnstein RA Chakravorty A Chan A Chen YC Choong WS Clark K Dukes EC Durandet C Felix J Gidal G Gu P Gustafson HR Ho C Holmstrom T Huang M James C Jenkins CM Kaplan DM Lederman LM Leros N Longo MJ Lopez F Lu L Luebke W Luk KB Nelson KS Perroud JP Rajaram D Rubin HA Teng PK Volk J White C White S Zyla P;HyperCP Collaboration 《Physical review letters》2002,88(11):111801
Using data collected with the HyperCP (E871) spectrometer during the 1997 fixed-target run at Fermilab, we report the first observation of the decay K--->pi(-)mu(+)mu(-) and new measurements of the branching ratios for K+/--->pi(+/-)mu(+)mu(-). By combining the branching ratios for the decays K+-->pi(+)mu(+)mu(-) and K--->pi(-)mu(+)mu(-), we measure Gamma(K+/--->pi(+/-)mu(+)mu(-))/Gamma(K+/--->all) = (9.8+/-1.0+/-0.5)x10(-8). The CP asymmetry between the rates of the two decay modes is [Gamma(K+-->pi(+)mu(+)mu(-))-Gamma(K--->pi(-)mu(+)mu(-))]/[Gamma(K+-->pi(+)mu(+)mu(-))+Gamma(K--->pi(-)mu(+)mu(-))] = -0.02+/-0.11+/-0.04. 相似文献
37.
Aderholz M Aggarwal MM Akbari H Allport PP Baba PV Badyal SK Barth M Baton JP Bingham HH Brucker EB Burnstein RA Campbell RC Cence R Chatterjee TK Clayton EF Corrigan G Coutures C De Prospo D Devanand De Wolf E Faulkner PJ Fretter WB Gupta VK Guy J Hanlon J Harigel G Harris F Jabiol MA Jacques P Jain V Jones GT Jones MD Jones RW Kafka T Kalelkar M Kasper P Kaul GL Kaur M Kohli JM Koller EL Krawiec RJ Lauko M Lys J Mann WA Marage P Milburn RH Miller DB Mittra IS Mobayyen MM Moreels J 《Physical review letters》1989,63(21):2349-2352
38.
PÉTER BAKÓ ATTILA MAKÓ GYÖRGY KEGLEVICH DÓRA K. MENYHÁRT TAMÁS SEFCSIK JENŐ FEKETE 《Journal of inclusion phenomena and macrocyclic chemistry》2006,55(3-4):295-302
The alkali metal- and ammonium picrate extracting ability of d-glucose- and d-mannose-based 15-crown-5 ethers and related lariat ethers was investigated in dichloromethane – water system. A heteroatom was waried in the crown ether containing a 4,6-O-benzylidene-α-d-glucopyranoside unit 6, (X=O), 2 (X=S) and 8a (X=NH). Extracting ability of the latter species (8a) was excellent (97–99%) in regard of all cations (Li+, Na+, K+, Rb+, Cs+ and NH4+) examined, it was not, howewer, selective. Introduction of a side arm on the nitrogen atom of 8a decreased the extracting ability, but increased the selectivity. In this series of compounds (8b–f, 4), 4 with a pyridylethyl substituent allowed the extraction of sodium picrate in 72%. The glucose-based macrocycles 8a, 8e and 8f formed a stronger complex with the cations examined than the mannose-based analogues 9a, 9e and 9f, that can be explained by the all-gauche conformation of the former ones. It was pointed out that in the case of crowns with tertiary amine moieties, the basicity increases the quantity of the picrates extracted. According to complex forming measurements by FAB-MS, the best sodium ion selectivity was achieved by the γ-hydroxypropyl substituted lariat ether (8e). Possible structures of the complexes formed by the two types of monosacharides with sodium cation were evaluated by molecule modelling calculations. 相似文献
39.
Jain V Harris FA Aderholz M Aggarwal MM Akbari H Allport PP Baba PV Badyal SK Barth M Baton JP Bingham HH Brucker EB Burnstein RA Campbell JR Cence RJ Chatterjee TK Clayton EF Corrigan G Coutures C Deprospo D Devanand De Wolf E Faulkner PJ Fretter WB Gupta VK Guy J Hanlon J Harigel GG Jabiol MA Jacques P Jones GT Jones MD Kafka T Kalelkar M Kasper P Kaul GL Kaur M Kohli JM Koller EL Krawiec RJ Lauko M Lys J Marage P Milburn RH Miller DB Mittra IS Mobayyen MM Moreels J Morrison DR Myatt G 《Physical review D: Particles and fields》1990,41(7):2057-2073
40.
Mattison TS Bofill J Busza W Eldridge T Friedman JI Fuess S Goodman MC Kendall HW Lyons T Magahiz R Mukherjee A Osborne LS Pitt R Rosenson L Sandacz A Tartaglia M Taylor FE Verdier R Whitaker JS Yeh GP Bogert D Burnstein R Morfin JG Stutte L Walker JK Abolins M Brock R Cohen A Ernwein J Owen D Slate J Weerts H 《Physical review D: Particles and fields》1990,42(5):1311-1330