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811.
In the path integral representation, the Hamiltonian in a quantum system is associated with the Hamiltonian in a classical system through the Weyl transformation. From this, it is possible to describe the time evolution in a quantum system by the Hamiltonian in a classical system. In a Bose system, the Weyl transformation is defined by the eigenstates of the canonical operators, since the Hamiltonian is given by a function of the canonical operators. On the other hand, in a Fermi system, the Hamiltonian is usually described by a function of the creation and annihilation operators, and hence the Weyl transformation is defined by the coherent states which are the eigenstate of an annihilation operator. Here, we formulate the Weyl transformation in Fermi systems in terms of the eigenstates of the canonical operators so as to clarify the correspondence between both systems. Using this, we can derive the path integral representation in Fermi systems. 相似文献
812.
1H and 19F spin-lattice relaxation times and nuclear Overhauser enhancement factors are reported for solutions of poly(fluoromethylene) in DMSO, and for poly(vinyl fluoride) in DMF. These results, together with literature values for other fluorinated ethylene polymers, show that substitutions of F for H on the chain backbone produce only mild changes in segmental mobility. 相似文献
813.
814.
815.
Norio Kashiwa Shin-ichi Kojoh Nobuo Kawahara Shingo Matsuo Hideyuki Kaneko Tomoaki Matsugi 《Macromolecular Symposia》2003,201(1):319-326
This paper describes a new synthetic route for polyolefinic graft block copolymers by adopting coupling reaction between terminally hydroxylated polyolefins and maleic anhydride grafted polyolefins. Terminally hydroxylated polypropylene (PP-OH) was coupled with maleic anhydride modified polyethylene (PE-g-MAH) and such ethylene-propylene random copolymer (EPR-g-MAH) to give polyolefinic graft block copolymers (PE-g-PP and EPR-g-PP, respectively). The formation of PE-g-PP was confirmed by enhancement on molecular weight and it brought about distinctive decrease in size of dispersed domain in its phase separation morphology. Occurrence of coupling reaction to give EPR-g-PP was indicated by extreme decrease in its solubility to n-decane and it led to unique morphology demonstrating lamella microstructure that had never been reported for a comparable polyolefin composite. 相似文献
816.
Hideyuki Kaneko Shin-ichi Kojoh Nobuo Kawahara Shingo Matsuo Tomoaki Matsugi Norio Kashiwa 《Macromolecular Symposia》2004,213(1):335-346
Polymacromonomers with polyolefin branches were successfully synthesized by free-radical homopolymerization of polyolefin macromonomer with a methacryloyl end group. Propylene-ethylene random copolymer (PER) with a vinylidene end group was prepared by polymerization using a metallocene catalyst. Then, the unsaturated end group was converted to a hydroxy end group via hydroalumination and oxidation. The PER with the hydroxy end group was easily reacted with methacryloyl chloride to produce methacryloyl-terminated PER (PER macromonomer; PERM). The free-radical polymerization of thus-obtained PERM was done using 2,2′-azobis(isobutyronitorile) (AIBN) as a free-radical initiator. From NMR analyses, the obtained polymers were identified as poly(PERM). Based on gel permeation chromatography (GPC), the estimated degree of polymerization (Dp) of these polymers were about 30. Thus, new class of polymacromonomers with polyolefin branches was synthesized. 相似文献
817.
Kazuki Matsuo Tadashi Yoshitake Eiji Yamaguchi Akichika Itoh 《Molecules (Basel, Switzerland)》2021,26(22)
We have developed a photochemical ATRA/ATRC reaction that is mediated by halogen bonding interactions. This reaction is caused by the reaction of malonic acid ester derivatives containing bromine or iodine with unsaturated compounds such as alkenes and alkynes in the presence of diisopropylethylamine under visible light irradiation. As a result of various control experiments, it was found that the formation of complexes between amines and halogens by halogen-bonding interaction occurs in the reaction system, followed by the cleavage of the carbon–halogen bonds by visible light, resulting in the formation of carbon radicals. In this reaction, a variety of substrates can be used, and the products, cyclopentenes and cyclopentanes, were obtained by intermolecular addition and intramolecular cyclization. 相似文献
818.
S. Leoni A. Bracco T. Døssing B. Herskind J.C. Lisle M. Matsuo E. Vigezzi J. Wrzesinski 《The European Physical Journal A - Hadrons and Nuclei》1999,4(3):229-231
The number of discrete rotational bands in the nucleus 168Yb is obtained by a fluctuation analysis of the rotational ridge structure in double and triple γ coincidence matrices. The
data are compared with cranked shell model calculations including a surface delta interaction. It is found that the number
of calculated bands strongly depends on the interaction strength V0, and agreement between data and calculations supports the standard value V0= 27.5/A MeV.
Received: 11 January 1999 相似文献
819.
H. Ohyama K. Sakamoto H. Sukizaki K. Takakura K. Hayama M. Motoki K. Matsuo H. Nakamura M. Sawada M. Midorikawa S. Kuboyama B. De Jaeger E. Simoen C. Claeys 《Materials Science in Semiconductor Processing》2008,11(5-6):217
The radiation damage induced by 2-MeV electrons and 70-MeV protons in p+n diodes and p-channel MOS transistors, fabricated in epitaxial Ge-on-Si substrates is reported for the first time. For irradiation above 5×1015 e/cm2, it is noted that both the reverse and forward current increase, and that the forward current is lower after irradiation for a forward voltage larger than about 0.5 V. The reason for this might be an increased resistivity of the Ge-on-Si substrate. For p-MOSFETs, for a 1×1016 e/cm2 dose, a slight negative shift of the threshold voltage and a decrease of the drain current for input and output characteristics have been observed. In addition, gm decreases after irradiation. The degradation of the transistor performance is thought to be due to irradiation-induced positive charges in the high-κ gate dielectric. The induced lattice defects are also mainly responsible for the leakage current increase of the irradiated diodes. 相似文献
820.
Kazuhiko Matsuo Kazuaki Kasai Kazunori Hosoe Iwao Funahashi 《Biomedical chromatography : BMC》2016,30(4):500-502
The ratio of ubiquinol‐10 in total coenzyme Q10 (TQ10) in human plasma has been proposed as a useful biomarker of oxidative stress. Since ubiquinol‐10 is easily oxidized in air, it is necessary to perform suitable processing at medical institutions prior to analysis. To establish stable storage conditions for blood to determine the ubiquinol‐10/TQ10 ratios properly, the effects of temperature conditions on the stability of ubiquinol‐10 were studied. Blood samples were collected from nine male Japanese volunteers. Changes in ubiquinol‐10/TQ10 ratios in blood samples were evaluated under three temperature conditions (room temperature, refrigerated and ice‐cooled). Plasma levels of ubiquinol‐10 and ubiquinone‐10 were determined by an HPLC system with electrochemical detection and the ubiquinol‐10/TQ10 ratios were calculated. We found that the ubiquinol‐10/TQ10 ratio was stable up to 8 or 4 h when blood samples were stored in refrigerator or ice‐cold container, respectively, and its decreases during these periods were <1.0%. We conclude that, in order to evaluate ubiquinol‐10/TQ10 ratios, blood samples should be stored in a refrigerator or an ice‐cold container, and processed for plasma separation within 4 h. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献