Note on the One-Dimensional Holstein-Hubbard Model

The one-dimensional Holstein-Hubbard model is studied. We show the uniqueness of the ground state and the ordering of energy levels.     

Columnar nanostructured polymer films containing ionic liquids in supramolecular one-dimensional nanochannels

Ionic liquids have attracted a considerable attention as the next generation electrolytes for energy devices. We have developed new free-standing and nanostructured polymer films in which ionic liquids are confined into one-dimensionally ordered nanochannels. These polymer films have been obtained by photopolymerization of hydrogen-bonded supramolecular columnar liquid-crystalline self-assemblies of an imidazolium-based ionic liquid and a wedge-shaped diol compound containing polymerizable groups. The macroscopically parallel alignment of the columnar structures on a glass substrate has been achieved by the application of mechanical shearing, and subsequently fixed into polymer films by UV irradiation. This ionic liquid-containing polymer film exhibits higher ionic conductivity than that of the previously reported one-dimensional polymer film obtained by in situ photopolymerization of a covalent-type columnar liquid-crystalline imidazolium salt. The noncovalent supramolecular approach to one-dimensionally ion-conductive polymer films has led to improvement on conductive properties. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 366–371     

Gold(I) Complexation of Phosphanoxy-Substituted Phosphaalkenes for Activation-Free LAuCl Catalysis

The phosphanoxy-substituted phosphaalkene bearing the P=C−O−P skeleton can be prepared from diphosphene Mes*P=PMes* (Mes*=2,4,6-tBu₃C₆H₂), and their use for catalysis is of interest. In this paper, complexation of the phosphanoxy-substituted phosphaalkenes with gold are investigated, and the catalytic activity of the mono- and bis(chlorogold) complexes are subsequently evaluated. Reaction of the P=C−O−P compound with (tht)AuCl (tht=tetrahydrothiophene) showed dominant coordination on the sp³ phosphorus, and complete coordination on the sp² phosphorus required removal of tetrahydrothiophene. Atoms In Molecules (AIM) analysis based on the X-ray structure of the mono(chlorogold) complex indicated a pseudo coordinating interaction between the gold center and the P=C unit. The bis(chlorogold) complexes displayed conformational isomerism, and catalyzed the cycloisomerization/alkoxycyclization of 1,6-enyne and for hydration of terminal alkyne without activation treatment. Even the mono(chlorogold) complexes catalyzed the alkoxycyclization reactions without a silver co-catalyst, indicating that the alcohols were effective in activating the AuCl unit.     

Shock reaction of hexane at 77, 193, and 273 K with special reference to shock pressure

Shock waves generated by projectile impacts were transmitted into hexane and the shocked hexane was analyzed by TCD-GC, FID-GC, GCMS, and FABMS for produced aliphatic hydrocarbons. The projectile length and its velocity were varied from 10 to 40 mm and from 220 to 1040 m/s, respectively. The initial temperature of the hexane was 77, 193 and 273 K. The major products detected throughout the reactions were hydrogen, light alkanes from C to C, and light alkenes from C to C. The minor products were heavy alkanes from C to C and soot-like materials. Experiments with varied projectile length revealed that the shock reaction occurred only while the shock wave was transmitted through hexane (about seconds). This short reaction time may be responsible for a lower yield of branched products in the shock reaction compared with yield produced by hexane pyrolysis in previous studies. In the shock reaction of hexane, the dehydrogenation was one of the important reactions and the recombination of hexyl radicals might play a role in the formation of -C. Experiments with varied initial temperature suggested that the molar yield of products depends not on the shock temperature but on the shock pressure, and that the reaction mechanisms for solid hexane and for liquid hexane are not identical. As the shock pressure increased, the relative yield of heavy products increased while that of light products decreased. This could be interpreted mainly by considering the activation volumes of the reaction involved. Received 12 September 1997 / Accepted 14 October 1997     

Application of underwater shock wave and laser-induced liquid jet to neurosurgery

Paper deals with applications of underwater shock waves to medicine. A historical development of underwater shock wave generation by using pulsed Ho:YAG laser beam irradiation in water is briefly described and an overview is given regarding potential applications of shock waves to neuro-surgery. The laser beam irradiation in a liquid-filled catheter produces water vapor bubble and shock waves intermittently produces micro-liquid jets in a controlled fashion from the exit of the catheter. Correlations between shock dynamics and bubble dynamics are emphasized. To optimize the jet motion, results of basic parametric studies are briefly presented. The liquid jet discharged from the catheter exit has an impulse high enough to clearly exhibit effectiveness for various medical purposes. In liquid jets we observed reasonably strong shock waves and hence invented a compact shock generator aiming to apply to microsurgery. We applied it to a rat's bone window and developed an effective method of brain protection against shock loading. The insertion of Gore-Tex® sheet is found to attenuate shock waves drastically even for very short stand off distance and its physical mechanism is clarified. The laser-induced liquid jet (LILJ) is successfully applied to soft tissue dissection. Animal experiments were performed and results of histological observations are presented in details. Results of animal experiments revealed that LILJ can sharply dissect soft tissue with a minimum amount of liquid consumption, while blood vessels larger than 0.2 mm in diameter are preserved. Shock waves and LILJ have a potential to be indispensable tools in neuro-surgery.This paper was based on work that was presented at the 2nd International Symposium on Interdisciplinary Shock Wave Research, Sendai, Japan, March 1–3, 2005.Communicated by K. Takayama PACS 42.62.Be, 47.40.-x, 42.62.-b     

Stress measurement by copper electroplating based on grain growth

This paper presents a stress measurement method using the grain-growth phenomenon in the copper-electroplated layer by cyclic loading. The growth rate of grains by cyclic loading is related to the stress amplitude. The relation between grain area and number of stress cycles was observed under various stress amplitudes and the relation between grain growth rate and the stress amplitude was obtained. The grain area was measured by an image-processing system using a personal computer. Because grain-growth rate depends on the amplitude of stress, surface stress can be estimated from the grain-growth rate based on this relation. For grain size in the range from 0.01 to 0.1 mm, stress in a very small region can be measured based on the growth of grains. Stress measurement was actually carried out using this method. The result showed that the error was less than 1.0 percent, confirming that this method is sufficiently accurate.