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81.
The spectral throughput of a vacuum-ultraviolet irradiation system at the SOR-RING facility was examined with various combinations of aluminum-and gold-coated optical elements in a 2.2-m modified Wadsworth monochromator. We found that the optimum was a combination of an aluminum-coated collimating mirror, concave grating, and plane deflecting mirror, and a combination of a gold-coated collimating mirror, concave grating and an aluminum-coated plane deflecting mirror in the wavelength regions 190-110 nm and 110-50 nm, respectively.  相似文献   
82.
A multiresidue analytical method was developed for the confirmation of benzylpenicillin (PCG), phenoxymethylpenicillin (PCV), oxacillin (MPIPC), cloxacillin (MCIPC), nafcillin (NFPC) and dicloxacillin (MDIPC) in bovine tissues using electrospray ionization liquid chromatography-tandem mass spectrometry (LC-ESI-MS-MS) with a product ion scan mode. All penicillins gave [M-H]-, [M-H-CO2]- and [M-H-141]- as the product ion, when [M-H]- was selected as the precursor ion. Combination of an ion-exchange cartridge clean-up and the LC-ESI-MS-MS method can reliably identify all of these penicillins fortified at a concentration of 0.05 mg/kg in bovine tissues, including liver, kidney and muscle. The limits of confirmation satisfy the maximum residue limits for each of the penicillins established by the World Health Organization, US Food and Drug Administration, European Union and Japan.  相似文献   
83.
127I M?ssbauer spectra of good quality were obtained at 20 K using a Zn127mTe source produced by high flux neutron irradiation of 66Zn-126Te at reactor core. The M?ssbauer spectra for KI and some iodine(III) compounds with absorption intensity of about 5% suggest that the 127I M?ssbauer spectroscopy is useful in elucidating the bonding nature of the iodine compounds. Preparative method of the M?ssbauer source and experimental technique are reported in detail.  相似文献   
84.
Submicron-sized styrene-methacrylic acid copolymer particles, which were produced by emulsion copolymerization, were changed to those having multihollow structure by treating stepwise the emulsion as follows. First alkali treatment was carried out at higher temperature than the glass transition temperature and subsequently the emulsion was cooled by keeping it at room temperature. This was named alkali/cooling method. The effects of methacrylic acid content, pH, time and temperature in the alkali treatment on the formation of multihollow structure were clarified.Part CLV of the series Studies on suspension and emulsion  相似文献   
85.
Poly(ethylene oxide-)-poly(1, 1-dimethyl-2, 2-dihexyldisilene) block copolymers (PEO-b-PMHS) were synthesized by the anionic polymerization of masked disilenes initiated with the potassium alkoxide of poly(ethylene glycol). The block copolymer self-assembled into polymer micelles in water accompanied by a transition in the polysilane conformation.  相似文献   
86.
Bowl‐shaped chiral homotriazacalixarenes were prepared by the cyclization reactions of chiral triamines with three equimolar amounts of bis(chloromethyl) phenols or bis(chloromethyl) phenol‐formaldehyde dimers in moderate yields. The corresponding acyclic phenol‐formaldehyde oligomers were also synthesized. The structural analysis of the macrocycles by nmr and circular dichroism spectra imply the existence of chiral transmission from the point chirality of the cysteine bridge to the cyclophane moiety. Their cyclic and acyclic compounds have a π‐base cavity large enough to include the ammonium ion.  相似文献   
87.
Characterization of clarithromycin polymorph was performed by solid-state cross polarization and magic angle spinning (CP/MAS) 13C-NMR spectroscopy. Two polymorphs, form II and form I, of clarithromycins indicated characteristic resonances of C1 carbonyl carbon at 176.2 and 175.2 ppm, respectively. Since each peak of C1 carbon was well separated in the spectrum of the two polymorphs, we performed quantitative analysis of the polymorphic fraction from the peak area of these peaks. The peak area of form I was found to linearly increase with an increase of its content, with a correlation coefficient of above 0.99. Solid-state NMR was found to be a useful technique to determine the characteristics of the polymorphic forms.  相似文献   
88.
New palladium(0) complexes with a variety of coordinated olefins [Pd(olefin)(PMePh2)2] (II) (olefin = styrene, ethyl methacrylate, methyl methacrylate, methyl acrylate, methacrylonitrile, and dimethyl maleate), were prepared by the reactions of [PdEt2(PMePh2)2] (I) with corresponding olefins in toluene. These complexes were characterized by means of elemental analysis, IR and 1H NMR spectroscopy and the chemical reactions. The dissociation of the coordinated olefin from complex II in solution was confirmed by spectroscopic studies of [Pd(mma)(PMePh2)2] (mma = methyl methacrylate). From the variable temperature NMR study, kinetic parameters for the dissociation process were determined as Ea = 7 kcal/mol, and ΔS3 (293 K) = -30 cal/deg · mol. Some new hydrido complexes, [Pd(H)ClL2] (IV) (L = PMePh2, PEtPh2 and PEt2Ph), were prepared by the reactions of [Pd(olefin)L2] with dry HCl.  相似文献   
89.
90.
Alkenylation reaction of alpha-halo carbonyl compounds with alkenylindiums proceeded via a radical process in the presence of triethylborane. Unactivated alkene moieties as well as a styryl group could be introduced by this method. The geometry of the carbon-carbon double bonds of the alkenylindiums was retained. Preparation of an alkenylindium via a hydroindation of 1-alkyne followed by radical alkenylation established an efficient one-pot strategy. [reaction: see text]  相似文献   
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