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351.
Kaori Yagi 《Tetrahedron》2006,62(20):4933-4940
CuCN-catalyzed reaction of the (1R)-isomer of 4-cyclopentene-1,3-diol monoacetate with TBDPSO(CH2)6MgCl produced an SN2-type product regioselectively in high yield. Mitsunobu inversion of the product and subsequent Claisen rearrangement furnished aldehyde with the two side chains, from which the title compounds were synthesized efficiently. 相似文献
352.
Kenji Nina Yuki Kimura Kaori Yokoyama Osamu Kido Gong Binyo Chihiro Kaito 《Physica E: Low-dimensional Systems and Nanostructures》2008,40(9):2995-2998
The formation process of MoO2 crystal from amorphous MoO3 film has been imaged by in situ observation with a transmission electron microscope. Selective growth of flower-shaped MoO2 crystals by heating above 673 K in vacuum was directly observed. Since the MoO2 crystal has metallic conductivity of the order of indium oxide film containing tin (ITO film), the thin film growth of the MoO2 phase has been discussed on the basis of a new substitute for ITO film. 相似文献
353.
In this paper, we will establish a discrete-time version of Clark(–Ocone–Haussmann) formula, which can be seen as an asymptotic expansion in a weak sense. The formula is applied to the estimation of the error caused by the martingale representation. Throughout, we use another distribution theory with respect to Gaussian rather than Lebesgue measure, which can be seen as a discrete Malliavin calculus. 相似文献
354.
Chelating porous membranes were prepared by radiation-induced graft polymerization of an epoxy-group-containing monomer onto a polyethylene flat sheet and subsequent conversion of the epoxy group to an iminodiacetate group as a chelate-forming group. The chelating group density on the resultant porous flat-sheet membrane of 1.0 mol/kg was comparable to that of commercially available chelating beads. The pure water permeability of the membrane was 40% that of the trunk porous membrane, which was used for microfiltration. During the permeation of a copper chloride solution through the membrane, diffusional mass-transfer resistance of copper ion was negligible, since the ion was transported by convective flow through the pore. The tensile strength and elongation at break of the membranes were measured as a function of dose of electron-beam irradiation, the degree of grafting, and the chelating group density to determine an applicable range for practical use. 相似文献
355.
Ionic liquids (ILs), which are used as solvents for chemical reactions, are different from conventional organic solvents owing to their designability. Physicochemical parameters of the ILs, such as polarity and viscosity, that affect chemical equilibria and reaction kinetics can be tuned by changing the combination of anions and cations or by varying the lengths of the alkyl chains present in the cations. We were interested in knowing how these physicochemical parameters affect fundamental chemical reactions in ILs. Therefore, in this personal account, we investigate our recent work on two different photochemical reactions in ILs, namely excited-state intramolecular proton transfer of hydroxyflavone and photodissociation of aminodisulfide, using time-resolved spectroscopic techniques. Interestingly, the roles of the ILs in these chemical reactions are quite different. The effect of the cationic species of the ILs (i. e., the head groups and number of alkyl carbons) on the solvation environment upon photoexcitation and reaction rate are discussed. 相似文献
356.
Takuya Hashimoto Kazunari Takagi Kenji Tsuda Michiyoshi Tanaka Kaori Yoshida Hiroaki Tagawa Masayuki Dokiya 《ChemInform》2001,32(10):no-no
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option. 相似文献
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Porphyrins bearing the redox-active phenylenediamine pendant groups are synthesized to afford dimensionally oriented π-conjugated systems. The structural and electronic characteristics depend on the atropisomers. In the fluorescence emission spectra, the emission from the porphyrin moiety is almost completely quenched. Zinc complexation of the αααα isomers gives the corresponding zinc porphyrins bearing four phenylenediamine strands. Treatment with a bidentate ligand, DABCO, leads to the sandwich dimer complex, in which the porphyrin moieties are surrounded by π-conjugated pendant groups. p-t-Butylcalix[4]arenes bearing four redox-active phenylenediamine pendant groups on the lower rim are synthesized and characterized both spectroscopically and electrochemically. The interconversion of the oxidation states of the pendant groups is demonstrated both chemically and electrochemically. 相似文献