A Complete Frequency-Field Chart for the Antiferromagnetic Resonance in MnF2

Antiferromagnetic resonance (AFMR) measurements on a well characterized single crystal sample of MnF₂ have been performed using various kinds of millimeter and submillimeter sources up to 570 GHz and a superconducting magnet up to 20 T. All the AFMR modes predicted from the theory have been observed. We report a complete frequency-field chart for these AFMR modes.     

Constraints on four-Fermi contact interactions from low-energy electroweak experiments

We investigate the constraints on four-Fermi contact interactions from low-energy lepton-quark and lepton-lepton scattering experiments – polarization asymmetries in electron (muon)-nucleon scattering experiments, cesium and thallium atom parity violation measurements, neutrino-nuclei and neutrino-electron scattering experiments. These constraints are then combined by assuming the lepton and quark universalities and gauge invariance of the contact interaction, which leave independent six lepton-quark and three pure-leptonic interactions. Impacts of these constraints on models with an additional -boson are briefly discussed. We also present updates of the low-energy constraints on the and parameters. Received: 28 November 1997 / Published online: 26 February 1998     

Fluorination with ionic liquid EMIMF(HF)2.3 as mild HF source

Hydrogen fluoride is a basic fluorinating reagent, but handling it is difficult. For this reason, some modified fluorinating reagents such as HF-pyridine, Et₃N-HF, and poly(hydrogen fluoride) complex have been developed. Those reagents, however, still require aqueous work-up procedures which generate hydrogen fluoride. Recently, ionic liquids have received much attention because of the ease in handling them and the possibility of non-aqueous work-up. An ionic liquid, 3-ethyl-1-methyimidazolium oligo hydrogen fluoride (EMIMF(HF)_2.3), which is stable in air and moisture, can be used as a hydrogen fluoride equivalent for some fluorination reactions; it does not require an aqueous work-up.     

Effects of phenylalaninol on centrally induced gastric acid secretion.

The effects of phenylalaninol (D-isomer) on gastric acid secretion and gastric ulcer were studied in rats. The compound reduced the gastric acid secretion stimulated by intracisternal thyrotropin releasing hormone and intravenous 2-deoxy-D-glucose, but not that stimulated by subcutaneous carbachol or histamine. Phenylalaninol prevented stress- and indomethacin-induced gastric ulcers. We conclude that phenylalaninol inhibits ulcer formation mainly by central inhibition of gastric acid secretion.     

Molecular dynamics simulation about porous thin-film growth in secondary deposition

The thin film growth has been confirmed to be assembled by an enormous number of clusters in experiments of CVD. Sequence of clusters’ depositions proceeds to form the thin film at short time as gas fluids through surface of substrate. In order to grow condensed thin film using series of cluster deposition, the effect of initial velocity, substrate temperature and density of clusters on property of deposited thin film, especially appearance of nanoscale pores inside thin film must be investigated. In this simulation, three different cluster sizes of 203, 653, 1563 atoms with different velocities (0, 10, 100, 1000 and 3000 m/s) were deposited on a Cu(0 0 1) substrate whose temperatures were set between 300 and 1000 K. Four clusters and one cluster were used in primary deposition and secondary deposition, respectively. We have clarified that adhesion between clusters and substrate is greatly influenced by initial velocity. As a result, the exfoliation pattern of deposited thin film is dependent on initial velocity and different between them. One borderline dividing whole region into porous region and nonporous region are obtained to show the effect of growth conditions on appearance of nanoscale pores inside thin film. Moreover, we have also shown that the likelihood of porous thin film is dependent on the point of impact of a cluster relative to previously deposited clusters.     

Sustainable Mizoroki-Heck reaction in water: remarkably high activity of Pd(OAc)2 immobilized on reversed phase silica gel with the aid of an ionic liquid

Palladium acetate immobilized on reversed phase amorphous silica gel with the aid of an ionic liquid, [bmim]PF6, was highly efficient in the promotion of the Mizoroki-Heck reaction in pure water without a ligand up to the sixth re-use, in 95% average yield with TON and TOF 1,600,000 and 71,000 (h(-1)), respectively.     

Diastereoselective radical hydrogenation of alpha-(1-Hydroxyalkyl)vinyl sulfoxides and sulfones controlled by intramolecular hydrogen bonding

The reaction of (S)-alpha-(1-hydroxyalkyl)vinyl sulfoxides (S)-5 with alkyl radicals and tributyltin hydride gave the addition-hydrogenation products with high diastereoselectivity, whereas the reaction with (R)-alpha-(1-hydroxyalkyl)vinyl sulfoxides (R)-5 resulted in complete recovery of the starting sulfoxides. Stereoselective intramolecular hydrogen bonding between the hydroxy group and the diastereotopic sulfonyl oxygen led to high diastereoselectivity in the radical reaction of alpha-(1-hydroxyethyl)vinyl sulfone 12. An important role of intramolecular hydrogen bonding on the diastereoselectivity as well as the reactivity toward alkyl radicals is discussed.     

Regularizations and superconformal anomalies

By using different regularization methods we demonstrate that supersymmetry invariance is maintained up to one-loop order in supersymmetric gauge theories and calculate the superconformal anomalies.