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51.
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53.
Junji Mizukado Yasuhisa Matsukawa Heng-dao Quan Masanori Tamura Akira Sekiya 《Journal of fluorine chemistry》2005,126(3):365-369
ROCHF2-type fluorinated ethers were synthesized by the reaction of hexafluoropropene oxide (HFPO) with alcohol or phenol. In this reaction, although the insertion reaction of difluorocarbene to OH bond and the nucleophilic attack of alcohol or phenol to HFPO were competition, the insertion reaction proceeded predominantly to give fluorinated ether in the case of low nucleophilic alcohol or phenol. In addition, high reaction pressure is advantageous to the selectivity of the fluorinated ethers in the reaction of HFPO with (CF3)2CHOH or C6F5OH. 相似文献
54.
Shiro Senrui Atsuro Kodama Masaaki Takehisa 《Journal of polymer science. Part A, Polymer chemistry》1974,12(10):2403-2417
The radiation-induced emulsion polymerization of ethylene in a continuous flow system was carried out at 100°C by using FC-143 and potassium myristate. The polymer concentration in the latex during the course of the polymerization oscillated several times and then approached a steady-state value in a few hours in the case of short residence time. The rate of polymerization was almost constant within the residence time range of 0.2–0.9 hr. This is explained by the kinetics assuming the same mechanism previously proposed in the batch system, that is, the number of polymer particles in this range is considered to be constant. Gel formation was observed at longer reaction times in spite of the continuous supply of myristate micelles, possibly because large polymer particles are produced in this stage. The concentration of carbonyl group in the polymer produced by chain transfer to absorbed myristate ion changes in the same way as the polymer concentration with reaction time. The methyl group in the polymer is produced mainly by chain transfer to the polymer, and the concentration is nearly constant during the polymerization except in the initial stage. The rate constants for the continuous polymerization were very different from the batch polymerization previously studied, despite their similarities in nature. The mass transfer rate of the emulsifier from the micelles to the polymer particles requires future study. 相似文献
55.
Yoshishige Sato Thoru Takahashi Toshio Saito Toshio Sato Masaaki Takehisa 《Radiation Physics and Chemistry》1993,42(4-6):621-624
Radiation sensitivities of
. pumilus and
spores were examined to bremsstrahlung of 5 MeV EB and Cobalt -60 γ rays in order to confirm the effects of radiation and dose rate. Biological indicators (SPORTROL, NAmSA, USA) were irradiated with the X ray in the dose rate range of 4.7–47kGy/h. D-value of
spores was 1.4–1.5 kGy, and that of
was 1.1–1.3 kGy. The D-values of
and
have very small dose rate dependences to X ray, and the D-values are similar to those of γ ray. Dose distribution by X-ray and γ irradiation was measured for cartons containing 32 unit dialyzers. The Dmax./Dmin. of the X-ray irradiation (1.2) was smaller than that of γ ray (1.3). 相似文献
56.
In this study photoinduced cation generation, based on the photochemical properties of malachite green (MG), was used for the surface design and in vitro photochemical control of cell adhesion and proliferation. The MG-derivatized surface was prepared by coating a photoreactive polymer as a substrate onto a poly(ethylene terephthalate) (PET) sheet. The photoreactive polymer was radical copolymer of styrene with the MG-derivatized monomer diphenyl(4-vinylphenyl)methane leucohydroxide (degree of substitution of MG unit: 12.4 mol%). Water contact angle measurements and X-ray photoelectron spectroscopy revealed high hydrophobicity and homogeneous distribution of the MG groups on the outermost surface of the coated film, respectively. When the coated film was exposed to ultraviolet light (UV) irradiation at wavelengths of 290-410 nm, a time-dependent color change of the film was observed from pale yellow, before irradiation, to green. These results indicated generation of cations on the film surface by photochemical cation generation of the MG groups, which was quantitatively characterized by force versus distance curves measurements in atomic force microscopic (AFM) observation using a carboxylated AFM tip. The seeding and culture of endothelial cells showed a marked reduction in adhesion on the nonirradiated coated film surface, whereas the UV-irradiated surface promoted cell adhesion and proliferation except for incubation in serum-free medium, which was similar to commercial tissue culture PET sheet. These observations may be due to adsorption of cell adhesive proteins, typified by fibronectin, in serum-containing medium onto the cationized photoreactive copolymer surface by electrostatic interactions. 相似文献
57.
Takeuchi T Ugata S Masuda S Matsui J Yane T Takase M 《Organic & biomolecular chemistry》2004,2(18):2563-2566
Atrazine imprinted synthetic polymers were prepared using a combination of methacrylic acid and 2-sulfoethyl methacrylate that bound and converted atrazine and other 6-chlorotriazine herbicides to less toxic compounds. A chloride at the 6-position of the triazines was converted to a methoxy group by the polymer in a methanol-containing solvent, where the imprinting effects enhanced the catalytic activity. Competitive inhibition of the atrazine methanolysis was observed in the presence of a structurally related binder, ametryn, suggesting that the catalytic reaction proceeded in the binding sites generated by the molecular imprinting process. 相似文献
58.
Yohsuke Yamamoto Shiro Matsukawa Shin-ya Furuta Kin-ya Akiba 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6-7):1375-1379
Solution and crystal structures of monocyclic pentacoordinate phosphoranes bearing two Martin ligands and two carbon substituents are described. When the two carbon substituents are different, relative apicophilicity of the two monodentate carbon substituents could be determined based on the equilibrium ratio of the pseudorotamers. In some cases, x-ray structural analysis could be carried out and the crystallized structure from CH 3 CN is consistent with the major pseudorotamer in solution (CD 3 CN). Furthermore, when the equilibrium ratio of pseudorotamers is almost unity, novel cocrystallization of two pseudorotamers in a single crystal was observed. 相似文献
59.
60.
Takao Okada Yukari Imamura Takehisa Matsuda 《Journal of polymer science. Part A, Polymer chemistry》2010,48(7):1485-1492
Polymerization of a trimethylene carbonate (TMC) in an aqueous solution was investigated by gel permeation chromatography, Fourier transform infrared spectroscopy, and nuclear magnetic resonance. The polymerization reaction proceeded rapidly in the aqueous solution and high conversion was achieved in a relatively short time. 1,3‐Propanediol (PPD) formed by hydrolysis of TMC was used as the initiator. The TMC oligomer obtained by ring‐opening polymerization had a TMC unit backbone with terminal 3‐hydroxypropyl groups at both chain ends. The oligomer underwent transesterification reaction with elimination of PPD, resulting in a gradual increase in the molecular weight of the product. The molecular weight was affected by the concentration of TMC. The thermal properties of the polymers were investigated by differential scanning calorimetry. Polymers within the molecular weight (Mn) range from 6.0 × 103 to 2.3 × 104 g/mol crystallized, and endothermic peaks corresponding to the melting temperature were observed. The glass transition temperature increased with the molecular weight of the polymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1485–1492, 2010 相似文献