Metal-free synthesis of reactive oligomers by ring-opening oligomerization of glycidyl phenyl ether initiated with tetra-n-butylammonium fluoride in the presence of various protic compounds

Metal-free ring-opening oligomerizations of glycidyl phenyl ether (GPE) were performed with tetra-n-butylammonium fluoride (n-Bu₄NF) as an initiator in the presence of protic compounds (RHs) as chain transfer agents (CTAs). The RHs having pKa between 4.66 and 15.5 enabled to serve as the CTA in this oligomerization system, leading to reactive oligomers with relatively controlled molecular weights having narrow molecular weight distributions bearing functional groups such as alkene, benzyl ether, alkyne, ester and methacrylate groups at initiating end.     

A study of the fermi surface of α-brass

Fermi surface of α-brass was investigated up to 24.6 at.% Zn by the rotatingspecimen method in the annihilation radiation. The anisotropy in the Fermi surface of α-brass was found to be similar to that of pure copper. It was also noted that the 〈111〉-neck radius of the alloys increase monotonically with increasing content of zinc.     

Cysteine cyclic pyrrole-imidazole polyamide for sequence-specific recognition in the DNA minor groove

Pyrrole-imidazole (PI) polyamides are small DNA-binding molecules that can recognize predetermined DNA sequences with high affinity and specificity. Hairpin PI polyamides have been studied intensively; however, cyclic PI polyamides have received less attention, mainly because of difficulties with their synthesis. Here, we describe a novel cyclization method for producing PI polyamides using cysteine and a chloroacetyl residue. The cyclization reaction is complete within 1 h and has a high conversion efficiency. The method can be used to produce long cyclic PI polyamides that can recognize 7 bp DNA sequences. A cyclic PI polyamide containing two β-alanine molecules had higher affinity and specificity than the corresponding hairpin PI polyamide, demonstrating that the cyclic PI polyamides can be used as a new type of DNA-binding molecule.     

A heuristic decomposition approach to optimal control in a water supply model

The optimal pump control problem in a water supply system can be formulated as a mixed integer programming problem. In general, this problem is very difficult to solve by conventional integer programming algorithms, because the number of decision variables is as large as the total number of combinations of pump stations and control periods. However, it possesses a certain block triangular structure, which offers an attractive computational scheme. Taking advantage of this structure, this paper proposes a heuristic decomposition algorithm for finding a good feasible solution to this type of mixed integer programming problems. Numerical results for an actual pump control problem are also reported.     

Color Appearance of a Patch Explained by RVSI for the Conditions of Various Colors of Room Illumination and of Various Luminance Levels of the Patch

Whenever we enter a space illuminated differently from a previous space whether in color or in illuminance, we can quickly adapt to the new atmosphere and can again perceive white for the originally white object; this is known as color constancy. This phenomenon is explained by rotation of the recognition axis of the recognized visual space of illumination (RVSI) toward the illumination color. The explanation then predicts that the color appearance of a test patch changes radically toward the opposite direction from the color of illumination when the physical property of the test patch is kept unchanged at a neutral white. This prediction was confirmed by Experiment 1, where eight different colors of illumination were employed. The test patch appeared very vivid in color and shifted toward the opposite direction from the color of the illumination. In RVSI theory the light source color mode is explained by the release of the test patch from the restriction of RVSI. The release can be achieved by increasing the luminance of the test patch and the color appearance of the patch should then return to its own color as it is no longer controlled by RVSI. In Experiment 2 these predictions were investigated by increasing the luminance of the test patch to a much higher level than that of the objects in the lit room fixed at an illuminance of about 1001x. The color appearance of the test patch indeed became the light source color and returned to the original neutral white. Emphasis was given in the course of the experiments that the subjects were observing the test patch presented in a real 3D space where the subjects also stayed inside so that they could properly construct RVSI for the space.     

Disappearance of the hindrance ofE1-transition involving loosely bound nucleon

AlthoughE1-transition between levels below giant dipole resonance are almost always strongly hindered, there are several exceptions as observed in¹¹Be and¹³C. These fastE1-transitions are studied by adopting a simple “cutoff” model, in which the behavior of single particle wave functions only outside of the nucleus contribute. The results are compared with the particle-GDR coupling model. The reason why theE1-hindrance disappears is explained. We also investigate the direct capture of thermal neutron by⁴⁰Ca andN=82 nuclei, where similar situation is observed. Further, the implication of the direct capture in multiple neutron capture is discussed.     

Determination of erosion rates with cosmic ray produced36Cl

We present results of the determination of³⁶C1 (T _1/2=3.0·10⁵a) in rock samples produced in situ by cosmic rays and natural radioactivities. These experiments were designed to determine the feasibility of using³⁶Cl for studying erosion processes in calcium rich minerals like limestone or dolomite. The³⁶Cl/Cl ratios in the samples have been determined with accelerator mass spectrometry (AMS) at the Munich accelerator laboratory. A first application is the investigation of the erosion in the last million years in Allchar (Yugoslavia) for the feasibility study of the geochemical²⁰⁵Tl solar neutrino experiment.Dedicated to Prof. Dr. P. Kienle on the occasion of his 60th birthday. Supported by DFG     

Feasibility studies of the geochemical solar neutrino experiment205Tl(v,e−)205Pb

New investigations on the signal-to-background ratio of the geochemical solar neutrino experiment²⁰⁵Tl(v,e^?)²⁰⁵Pb using thallium minerals from Allchar (Yugoslavia) are presented. The contributions of several background processes producing²⁰⁵Pb induced by natural radioacitivities, stopped negative muons and fast muons are estimated. The production rate of²⁰⁵Pb by cosmic ray muons, derived from experimental investigations with 120, 200 and 280 GeV muons at the high energy muon channel of CERN, is significantly higher than expected by former estimations. The feasibility of the geochemical²⁰⁵T1 solar neutrino experiment is discussed.     

Selective colorimetric determination of p-haloaniline in a mixture witho-haloaniline by the reaction with chloranil

Summary p-Haloanilines react with chloranil to develope an intense color (_max: 545 nm), whileo-haloanilines do not. This difference in reaction has been applied to the selective determination ofp-haloanilines in a mixture witho-haloaniline.

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Zusammenfassung p-Halogenaniline geben mit Chloranil eine intensive Farbreaktion (_max= =545 nm), während die entsprechenden o-Verbindungen dies nicht tun. Auf dieser Grundlage wurde eine selektive Bestimmungsmethode für p-halogenierte Aniline in Gemischen mit o-halogenierten Anilinen ausgearbeitet.

     

Improvement of the zeolite catalyst for olefin synthesis from methanol by regulating the shape factor with the aid of seed crystals

By the use of seed crystals in the initial stage of preparation of a new type of zeolite for olefin synthesis, shape and size distribution of the zeolite could be regulated uniformly, and the catalyst performance was improved markedly especially with respect to olefin selectivity and the catalyst life.

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