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61.
Sasaki S Bando T Minoshima M Shimizu T Shinohara K Takaoka T Sugiyama H 《Journal of the American Chemical Society》2006,128(37):12162-12168
We designed and synthesized pyrrole (Py)-imidazole (Im) hairpin polyamide 1-(chloromethyl)-5-hydroxy-1,2-dihydro-3H-benz[e]indole (seco-CBI) conjugates 1 and 2, which target both strands of the double-stranded region of the human telomere repeat sequences, 5'-d(TTAGGG)(n)-3'/5'-d(CCCTAA)(n)-3'. High-resolution denaturing polyacrylamide gel electrophoresis demonstrated that conjugates 1 and 2 alkylated DNA at the 3' A of 5'-ACCCTA-3' and 5'-AGGGTTA-3', respectively. Cytotoxicities of conjugates 1 and 2 were evaluated using 39 human cancer cell lines; averages of log IC(50) values for conjugates 1 and 2 were -6.96 (110 nM) and -7.24 (57.5 nM), respectively. Conjugates 1 and 2 have potential as antitumor drugs capable of targeting telomere repeat sequence. 相似文献
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64.
Toshiyasu Arai 《Archive for Mathematical Logic》2002,41(2):123-153
We formulate epsilon substitution method for theories (H)α0 of absolute jump hierarchies, and give two termination proofs of the H-process: The first proof is an adaption of Mints M,
Mints-Tupailo-Buchholz MTB, i.e., based on a cut-elimination of a specially devised infinitary calculus. The second one is
an adaption of Ackermann Ack. Each termination proof is based on transfinite induction up to an ordinal θ(α0+ ω)0, which is best possible.
Received: 19 April 1999 / Published online: 20 December 2001 相似文献
65.
Iwamatsu Si S Vijayalakshmi PS Hamajima M Suresh CH Koga N Suzuki T Murata S 《Organic letters》2002,4(7):1217-1220
[reaction: see text] Photorearrangement of tetraalkoxycarbonyl-substituted cyclohexadiene derivatives of C(60) yields not only well-known bis(fulleroid) but also bis(methano)fullerene. Existence of a labile and structurally new intermediate is observed in the reaction mixture. The discovery of the compound suggests the existence of another possible pathway giving those two products other than the widely accepted [4 + 4]/[2 + 2 + 2] mechanism. 相似文献
66.
Shizuaki Murata Toshiyasu Suzuki Akira Yanagisawa Seiji Suga 《Journal of heterocyclic chemistry》1991,28(2):433-438
Reaction of 2,2′-dilithio-1,1′-binaphthyl with selenium followed by air oxidation gives a mixture of dinaph-thoselenophene and dimer and oligomers of 2,2′-diseleno-1,1′-binaphthyl. 2,2′-Dilithio-1,1′-biphenyl reacts with selenium to afford dibenzo[c,e][1,2]diselenin. Structures of the dimeric 2,2′-diseleno-1,1′-binaphthyl and dibenzo[c,e][1,2]diselenin have been confirmed by X-ray crystallographic analyses. Similar reaction of 2,2′-dilithio-1,1′-binaphthyl with sulfur or tellurium gives a mixture of dinaphthothiophene and dinaphtho[2,1-c:-1′,2′-e][1,2]dithiin or a mixture of dinaphthotellurophene and oligomer of 2,2′-ditelluro-1,1′-binaphthyl, respectively. Dibenzotellurophene and oligomer of 2,2′-ditelluro-1,1′-biphenyl are obtained from reaction of 2,2′-dilithio-1,1′-biphenyl with tellurium. 相似文献
67.
68.
Dr. Keisuke Fujimoto Dr. Seiichiro Izawa Ayumu Takahashi Dr. Toshiyasu Inuzuka Kazutaka Sanada Prof. Dr. Masami Sakamoto Dr. Yasuo Nakayama Prof. Dr. Masahiro Hiramoto Prof. Dr. Masaki Takahashi 《化学:亚洲杂志》2021,16(6):690-695
Curved perylene diimides fused with seven-membered rings have been synthesized using a regioselective bay-functionalization method and Pd-catalyzed intramolecular C−H/C−Br coupling reaction. X-Ray analysis and temperature-dependent NMR spectroscopy revealed the curved molecular structure with a certain degree of conformational flexibility. The curved and expanded π-conjugation altered the electronic properties while retaining the intrinsic properties of the parent perylene diimide. Despite the absence of solubilizing N-substituents, the curved perylene diimides showed sufficient solubility for application in solution-processed organic photovoltaic devices. The devices showed superior performance with a power conversion efficiency of up to 2.76% due to suppressed charge recombination. Our detailed investigations suggest that the introduction of a curved structure enables the removal of the bulky N-substituents, which is an effective way to achieve a thin-film morphology suitable for photoelectric conversion. 相似文献
69.
Hinderhofer A Heinemeyer U Gerlach A Kowarik S Jacobs RM Sakamoto Y Suzuki T Schreiber F 《The Journal of chemical physics》2007,127(19):194705
The optical properties of pentacene (PEN) and perfluoropentacene (PFP) thin films on various SiO(2) substrates were studied using variable angle spectroscopic ellipsometry. Structural characterization was performed using x-ray reflectivity and atomic force microscopy. A uniaxial model with the optic axis normal to the sample surface was used to analyze the ellipsometry data. A strong optical anisotropy was observed, and enabled the direction of the transition dipole of the absorption bands to be determined. Furthermore, comparison of the optical constants of PEN and PFP thin films with the absorption spectra of the monomers in solution shows significant changes due to the crystalline environment. Relative to the monomer spectrum, the highest occupied molecular orbital to lowest unoccupied molecular orbital transition observed in PEN (PFP) thin film is reduced by 210 meV (280 meV). A second absorption band in the PFP thin film shows a slight blueshift (40 meV) compared to the spectrum of the monomer with its transition dipole perpendicular to that of the first absorption band. 相似文献
70.
Koch N Gerlach A Duhm S Glowatzki H Heimel G Vollmer A Sakamoto Y Suzuki T Zegenhagen J Rabe JP Schreiber F 《Journal of the American Chemical Society》2008,130(23):7300-7304
The interfaces formed between pentacene (PEN) and perfluoropentacene (PFP) molecules and Cu(111) were studied using photoelectron spectroscopy, X-ray standing wave (XSW), and scanning tunneling microscopy measurements, in conjunction with theoretical modeling. The average carbon bonding distances for PEN and PFP differ strongly, that is, 2.34 A for PEN versus 2.98 A for PFP. An adsorption-induced nonplanar conformation of PFP is suggested by XSW (F atoms 0.1 A above the carbon plane), which causes an intramolecular dipole of approximately 0.5 D. These observations explain why the hole injection barriers at both molecule/metal interfaces are comparable (1.10 eV for PEN and 1.35 eV for PFP) whereas the molecular ionization energies differ significantly (5.00 eV for PEN and 5.85 eV for PFP). Our results show that the hypothesis of charge injection barrier tuning at organic/metal interfaces by adjusting the ionization energy of molecules is not always readily applicable. 相似文献