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191.
We present results on charged current inclusive neutrino and antineutrino scattering in the neutrino energy range 30–200 GeV. The results include a) total cross-sections; b)y distributions; c) structure functions; and d) scaling violations observed in the structure functions. The results, as well as their comparison with the results of electron and muon inclusive scattering, are in agreement with the expectations of the quark parton model and QCD.  相似文献   
192.
193.
Summary The addition of two nitrile ligands to the complex Re2Cl4-(dppm)2 (dppm= 1,2-bis(diphenylphosphine)methane)in CH2Cl2 solution has been investigated electrochemically. Upon addition of one equivalent of nitrile NCR (R = aromatic or aliphatic group) to the CH2Cl2/0.1m tetra-N-butylammonium hexafluorophosphate (TBAH) solution, Re2Cl4(dppm)2(NCR) is formed immediately, without dissociation of chloride; electrochemical investigation indicates this nitrile addition is reversible upon oxidation of the dirhenium complex. On addition of two or more equivalents of nitrile, a slow ligand substitution takes place with addition of a second nitrile and concomitant loss of a chloride ion to form [Re2Cl3-(dppm)2(NCR)2]+. The rate of addition of nitrile to Re2Cl4(dppm)2(NCR) appears to depend on the electrondonating or electron-withdrawing abilities of the ligand. The change from monoadduct to diadduct was followed with differential pulse voltammetry for various concentrations of added nitrile. The addition was found to be first order in nitrile.  相似文献   
194.
We report on results from a study of hadron-energy distributions for ν and ν inclusive neutral current interactions. There is no significant variation of the neutral to charged current total cross-section ratios Rν and Rν with neutrino energy. The space-time structure of neutral currents is dominated by V?A, with a significant admixture of V+A. The Weinberg-Salam model is in agreement with all data if sin2θw=0.24±0.02.  相似文献   
195.
Two semiempirical methods (MNDO and AM1), a molecular mechanics technique (MM2) and two ab initio approaches (6–31G* full optimization and 3–21G/6–31G*) were used to calculate the ordering of and energy difference between conformers in 1,3-dichloropropane. The semiempirical methods did not order the conformers properly or predict correct energy differences. Both ab initio methods ordered the conformers and predicted energy differences correctly, with the 6–31G* full optimization performing slightly better. The MM2 results were presented for calculations involving a force field with no hydrogens and a full force field of all atoms. The full force field properly ordered the conformers but did not correctly predict the energy differences. The nonhydrogen field ordered the conformers based on the Cl…Cl nonbonded distance. The data show that conformer stability is not a simple matter of maximizing the Cl…Cl nonbonded distance, but is also related to some other stabilizing interaction(s).  相似文献   
196.
Compounds of the general formula [ORe(OR)Cl2(PPh3)2] and [ORe(OEt)Cl2(PPh3)(py)], where R=alkyl or aryl and py=a substituted pyridine, were synthesized and their voltammetric behaviour investigated. For the former, the electron-transfer mechanism was observed to be dependent on solvent. In dry MeCN, a quasi-reversible oxidation and a reduction followed by a chemical reaction was observed. There were indications of nucleophilic attack on electrochemically generated [ORe(OEt)Cl2(PPh3)2]+, forming an unstable species whose reduction potentials were strongly dependent on the identity of the nucleophile. Voltammetric and spectroscopic observations of the oxorhenium(V) alkoxypyridine complex indicate the pyridine to be labile in halogenated hydrocarbon solvents but not in Me2CO, MeCN, or CCl4. Electrochemical generation of [ORe(OEt)Cl2(PPh3)(ClxCyHz)]+ (x=1,2, or 3; y=1 or 2; z=2,3, or 4) appears to be followed by transfer of a hydrogen atom from the solvent to form [(HO)Re(OEt)Cl2(PPh3)]+. Various pyridine complexes of this type were preparedvia substitution reactions under mild conditions. Varying the reaction conditions allowed the synthesis oftrans-dioxotetrapyridyl complexes in excellent yield.  相似文献   
197.
Analytical methodology is described for determining residues of the synthetic anabolic steroid trenbolone acetate (TBA) and its hydrolysis product trenbolone (TBOH) in admixture in animal chow, human urine, and wastewater. Benzene extracts of the substrates are subjected to liquid-liquid partitioning, further cleanup on a column of silica gel, and direct analysis by high pressure liquid chromotography or derivatization with pentafluoropropionic anhydride and analysis by electron capture gas chromatography. Satisfactory recoveries were obtained with both compounds from all three substrates. Residue levels of TBA and TBOH as low as 0.32 and 0.04 ppm, respectively, could be detected in chow; about 0.6 ppb of each compound could be detected in urine and wastewater. Thin layer chromatographic behavior of the two compounds in 7 solvent systems and other ancillary analytical data are also presented.  相似文献   
198.
Summary Bimetallic complexes of the general formula [Cl3(PPh3)2ReIII(NCArCN)ReIII(PPh3)2Cl3] (where NCArCN represents an aromatic dinitrile) have been prepared and their solution phase electrochemistry examined. Each of these complexes undergoes two one-electron metal-centred oxidations. The potential difference between these oxidations gives a measure of the stability of the ReIII/ReIV mixed-valence state toward disproportionation, and ranges from <0.050 V in the most weakly coupled system (4,4-biphenyldicarbonitrile bridge) to ca. 0.200 V for the most strongly interacting metal centres (9,10-dicyanoanthracene bridge). Likewise, all of the complexes show two one-electron transfers in either simultaneous or sequential fashion depending on the nature of the bridge.  相似文献   
199.
The potential K-region metabolites, trans- and cis-5,6-dihydroxy-7-methyl-5,6-dihydrobenz[c]acridine, 5,6-epoxy-7-methyl-5,6-dihydrobenz[c]acridine and 5-hydroxy-7-methylbenz[c]acridine, of 7-methylbenz[c]acridine have been synthesised.  相似文献   
200.
N.L. Holder  B. Fraser-Reid 《Tetrahedron》1973,29(24):4077-4082
A study of the mass spectra of ethyl 2,3-dideoxy-α-d-glycero-hex-2-enopyranosid-4-ulose1a, its 6-0-acetyl derivative1b, and methyl 3,4-dideoxy-α-d-glycero-hex-3-enopyranosidulose2a indicates that the main fragmentation of these compounds occurs by a retro-Diels-Alder type cleavage. Recognition of the ions produced by this cleavage provides a means of allocating the position of the α,β-unsaturated chromophore in carbohydrate enones. Fragmentation of molecular ions of1a and1b also occurred by direct loss of individual ring substituents to give ions which retain the pyranoid nucleus. The fragmentation pathways suggested are supported by accurate mass measurements of the salient fragment ions of1a.  相似文献   
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