Komplexkatalyse : VI. Ir-spektroskopische untersuchung der reaktion von nitrosylmolybdänkomplexen mit C2H5AlCl2, (C2H5)3Al,AlCl3 und kohlenmonoxid,ein beitrag zur klärung der struktur des katalytisch aktiven komplexes für die olefinmetathese

The reaction of di- and mono-nitrosylmolybdenum complexes with C₂H₅-AlCl₂, AlCl₃ and Al(C₂H₅)₃ under argon and CO was followed IR-spectroscopically. Some conclusions were reached concerning the nature of the catalyticactivity of the complex in olefin metathesis.     

Reductive nitrosation of molybdenum and tungsten halides II. One-stage synthesis of phosphine oxide substituted mononitrosyltrichloro-, and dinitrosyldichloro-molybdenum derivatives

The reductive nitrosation of MoCl₅ with NO in the presence of PPh₃ in CH₂Cl₂ solution gives Mo(NO)Cl₃ (OPPh₃)₂ as an intermediate and Mo(NO)₂ Cl₂(OPPh₃)₂ as a final product. In benzene solution the final product of the reaction is Mo(NO)₂Cl₂(OPPh₃)₂·2C₆H₆.     

Polarographisches Verhalten von 1,2,3-Cyclohexantrion-trioxim in sauren Lösungen

The deoximation kinetics of 1,2,3-cyclohexanetrione trioxime was studied polarographically in 0.5 and 1.0M-HClO₄ solutions. From the three vicinal oxime groups, that in position 2 is hydrolysed by protonisation, followed by water uptake and hydroxylamine loss. The probable mechanism of the deoximation was proved by the study of the polarographic behaviour of 1,2,3-cyclohexanetrione-1,3-dioxime and by means of amperometric determination of the unchanged trioxime with Ni(II)-salt.     

ESR spectrometer with a loop-gap resonator for cw and time resolved studies in a superconducting magnet

The design and performance of an electron spin resonance spectrometer operating at 3 and 9 GHz microwave frequencies combined with a 9-T superconducting magnet are described. The probehead contains a compact two-loop, one gap resonator, and is inside the variable temperature insert of the magnet enabling measurements in the 0-9T magnetic field and 1.5-400 K temperature range. The spectrometer allows studies on systems where resonance occurs at fields far above the g approximately 2 paramagnetic condition such as in antiferromagnets. The low quality factor of the resonator allows time resolved experiments such as, e.g., longitudinally detected ESR. We demonstrate the performance of the spectrometer on the NaNiO2 antiferromagnet, the MgB2 superconductor, and the RbC60 conducting alkaline fulleride polymer.     

Nica’s <Emphasis Type="Italic">q</Emphasis>-Convolution is Not Positivity Preserving

It is shown that the q-convolution of Nica is not positivity preserving unless q=0 or q=1, i.e. the q-convolution of two probability measures with finite moments of all orders is not necessarily a probability measure.Supported by Grant-in-Aid for JSPS Fellows     

Monolithic carrier-envelope phase-stabilization scheme

A new scheme for stabilizing the carrier-envelope (CE) phase of a few-cycle laser pulse train is demonstrated. Self-phase modulation and difference-frequency generation in a single periodically poled lithium niobate crystal that transmits the main laser beam allows CE phase locking directly in the usable output. The monolithic scheme obviates the need for splitting off a fraction of the laser output for CE phase control, coupling into microstructured fiber, and separation and recombination of spectral components. As a consequence, the output yields 6-fs, 800-nm pulses with an unprecedented degree of short- and long-term reproducibility of the electric field waveform.     

Intranasal irradiation with the xenon chloride ultraviolet B laser improves allergic rhinitis

We earlier reported that the 308 nm xenon chloride (XeCl) ultraviolet B (UVB) laser is highly effective for the treatment of inflammatory skin diseases. Since UVB irradiation has been shown to exert both local and systemic immunosuppression, we investigated the clinical efficacy of UVB irradiation in allergic rhinitis. In an open study, groups of patients with severe allergic rhinitis received intranasal irradiation with a 308 nm XeCl UVB excimer laser for two weeks. In the low-dose group (n=10), treatment was given twice weekly, starting with 0.25x the individual minimal erythema dose (MED), whereas patients in the medium-dose group (n=8) were treated four times weekly, starting with 0.4x MED. In each group, the dosage was gradually increased. Evaluation was based on the symptom scores. The effect of the XeCl laser on the skin prick test reaction was also studied. In the low-dose group, seven patients completed the study, and there was no improvement in the nasal symptoms. In the medium-dose group, the XeCl UVB irradiation significantly inhibited the rhinorrhoea, the sneezing, the nasal obstruction and the total nasal score (p<0.05). The XeCl UVB excimer laser also inhibited the allergen-induced skin prick test in a dose-dependent manner. These results suggest that the XeCl UVB excimer laser might serve as a new therapeutic tool in the treatment of allergic rhinitis.     

Weak type inequalities for the Walsh and bounded Ciesielski systems

We investigate both the Walsh system and the bounded Ciesielski systems, which can be obtained from the spline systems of order (m,k) in the same way as the Walsh system can be obtained from the Haar system. We show that the maximal operator of the Fejér means of the Walsh-- and Ciesielski--Fourier series is bounded from the Hardy space H _1/2 to the space weak L_1/2if m -1, |k| m+1. As a consequence, we obtain a new proof for the fact that the Fejér means of the Walsh-- or Ciesielski--Fourier series of a function f L ₁ converge to f a.e.