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排序方式: 共有233条查询结果,搜索用时 187 毫秒
61.
Manabu Tsumura Takahisa Iwahara Toshifumi Hirose 《Journal of polymer science. Part A, Polymer chemistry》1996,34(15):3155-3161
The polycarbosilanes (PCS) with meta-linkage bending unit ((SINGLE BOND)Me2Si(SINGLE BOND)m(SINGLE BOND)C6H4(SINGLE BOND)Me2Si(SINGLE BOND)CH2CH2(SINGLE BOND)) were successfully synthesized in mild conditions by hydrosilylation in the presence of [Pt{(CH2(DOUBLE BOND)CHSiMe2)2O}2]. The PCS obtained were soluble in various solvents owing to the lowering of the crystallinity. These properties are well compared with those of the PCS [(SINGLE BOND)Me2Si(SINGLE BOND)p(SINGLE BOND)C6H4(SINGLE BOND)Me2Si(SINGLE BOND)CH2CH2(SINGLE BOND)]n. © 1996 John Wiley & Sons, Inc. 相似文献
62.
Stefan Machill Takahisa Shodai Yoji Sakurai Jun-ichi Yamaki 《Journal of Solid State Electrochemistry》1999,3(2):97-103
Tin-based composite oxide materials have received considerable attention as potential anode materials for rechargeable lithium
batteries. In this contribution we present the results of our investigations of the SnOB2O3P2O5 system. We have investigated its electrochemical properties and especially its cycling performance. A focus of our interest
was to explain the structural changes which occur during lithium cycling and their strong dependence on the preparation method.
A part of the SnO component was converted into a very stable metallic phase. In addition, a decrease was observed in capacity
owing to the formation of isolated and inactive tin grains. We also report on structural changes in the B2O3P2O5 matrix.
Received: 2 October 1997 / Accepted: 3 July 1998 相似文献
63.
Takakazu Yamamoto Yukiko Muramatsu Takahisa Shimizu Wataru Yamada 《Macromolecular rapid communications》1998,19(5):263-266
π-Conjugated polymers bearing nitro substituent(s), e.g., poly(aryleneethynylene) (PAE) type polymers and poly(4,8-dinitroanthraquinone-1,5-diyl) P(4,8-NO2-1,5-AQ), show semiconducting properties with electrical conductivities of an order of 10−7 to 10−6 S · cm−1 at room temperature without special oxidation and reduction of the polymer. P(4,8-NO2-1,5-AQ) shows a large shift of phase in alternating current (ac) measurements and a unique magnetism at low temperature. 相似文献
64.
Katsuhiro Nose Takahisa Omata Shinya Otsuka-Yao-Matsuo Hideaki Maeda 《Journal of luminescence》2007,126(1):21-26
The role of organic amines in the colloidal synthesis of CdSe quantum dots (QDs) has been studied. CdSe QDs were synthesized from the source solutions containing 5 vol% of amines having various alkyl chain lengths, stereochemical sizes and electron donation abilities. The role of the additional amines was evaluated on the basis of the photoluminescence (PL) properties such as PL wavelength and intensity of the obtained CdSe QDs. The observed PL spectra were explained by the fact that the amines behaved as capping ligands on the surface of the QDs in the product colloidal solution and complex ligands for cadmium in the source solutions. It was shown that the particle size was controlled by the diffusion process depending on the mass and stereochemical shape of the amines, and the luminescence intensity increased with the increasing electron donation ability and capping density of the amines. 相似文献
65.
Oikawa M Saito T Takahisa K Suga Y Kino K Nakagawa T Tohei T Abe K Ueno H 《Physical review letters》2000,84(11):2338-2341
Out of plane measurements of the angular correlations for the 12C(e, e(')n) reaction have been performed for the first time in the giant resonance region. The cross sections were directly separated into the longitudinal and transverse, longitudinal-transverse, and transverse-transverse components. The cross section at the peak of the giant resonance ( omega = 22.5 MeV) has been found to be almost all longitudinal. It was reproduced by the multipole expansion with E0 and E2 components besides E1. The longitudinal-transverse component might have a maximum around 24 MeV. The transverse-transverse component is very small over the giant resonance. 相似文献
66.
Mizu M Koumoto K Anada T Matsumoto T Numata M Shinkai S Nagasaki T Sakurai K 《Journal of the American Chemical Society》2004,126(27):8372-8373
A beta-(1 --> 3)-d-glucan schizophyllan (SPG) forms a stoichiometric complex with some polynucleotides. This communication describes our attempt to apply the SPG complex to deliver CpG DNA to endosomes to enhance cytokine secretion. To increase cellular uptake, we introduced spermine, arginine-glycine-aspartic acid tripeptide, octaarginine, or cholesterol to the SPG side chain. The chemically modified SPG showed essentially no cytotoxicity. When CpG DNA complex made therefrom was exposed to macrophages, dramatic enhancement in the cytokine secretion was observed. It increased 5-10 times from the naked dose and 100 times from the background. This performance promises that SPG can be an excellent carrier for CpG DNA. 相似文献
67.
68.
Masashi Harada Masayuki Ohya Takahisa Suzuki Daisuke Kawaguchi Atsushi Takano Yushu Matsushita 《Journal of Polymer Science.Polymer Physics》2005,43(10):1214-1219
Three poly(4‐trimethylsilylstyrene)‐block‐polyisoprenes (TIs), the molecular weights of which were 82,000, 152,000 and 291,000 (TI‐82K, TI‐152K, and TI‐291K), were synthesized by sequential anionic polymerizations. The component polymers were a miscible pair that presented a lower critical solution temperature phase diagram if blended. The TI phase behavior was investigated with transmission electron microscopy. The order–disorder transition could be observed at a temperature between 200 °C (the ordered state) and 150 °C (the disordered state) for the block copolymer TI‐152K. The block copolymer TI‐82K presented the disordered state at 200 °C, whereas TI‐291K was in the ordered state at 150 °C. With the Flory–Huggins interaction parameter between poly(4‐trimethylsilylstyrene) and polyisoprene, which was evaluated by small‐angle neutron scattering for the block copolymers, the TI phase behavior could be reasonably explained by mean‐field theory. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1214–1219, 2005 相似文献
69.
Yoshimoto Abe Akira Kaijou Nobuhiro Shintani Yukinori Nagao Takahisa Misono 《Journal of polymer science. Part A, Polymer chemistry》1987,25(6):1671-1679
The reaction in different molar ratios of trimethylchlorosilane to silicic acid offered partially silylated silicic acids PSSX (X = OH) with various degrees of silylation. Esterification and acetylation of PSSX (X = OH) with 1-butanol or acetylchloride gave polysiloxanes PSSX (X = OBun and OCOCH3). Some of them showed an excellent spinnability and provided a fine fiber with a length of about 250 cm. A fiber drawing test from concentrated PSSX solutions of various solvents revealed that spinnability markedly depended on the DS, functional group X of PSSX, and solvent. Spinnability may also be correlated to solubility parameter of PSSX and solvent. 相似文献
70.
Crystallographic Evidence for Direct Metal–Metal Bonding in a Stable Open‐Shell La2@Ih‐C80 Derivative 下载免费PDF全文
Lipiao Bao Dr. Muqing Chen Changwang Pan Takahisa Yamaguchi Prof. Tatsuhisa Kato Prof. Marilyn M. Olmstead Prof. Alan L. Balch Prof. Takeshi Akasaka Prof. Xing Lu 《Angewandte Chemie (International ed. in English)》2016,55(13):4242-4246
Endohedral metallofullerenes (EMFs) have novel structures and properties that are closely associated with the internal metallic species. Benzyl radical additions have been previously shown to form closed‐shell adducts by attaching an odd number of addends to open‐shell EMFs (such as Sc3C2@Ih‐C80) whereas an even number of groups are added to closed‐shell EMFs (for example Sc3N@Ih‐C80). Herein we report that benzyl radical addition to the closed‐shell La2@Ih‐C80 forms a stable, open‐shell monoadduct instead of the anticipated closed‐shell bisadduct. Single‐crystal X‐ray diffraction results show the formation of a stable radical species. In this species, the La?La distance is comparable to the theoretical value of a La?La covalent bond and is shorter than reported values for other La2@Ih‐C80 derivatives, providing unambiguous evidence for the formation of direct La?La bond. 相似文献