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71.
We propose techniques of hologram replication in glass plates and reconstruction on another film by corona charging. A surface
relief hologram on an azobenzene polymer film was recorded in the form of electric polarization in glass plates that include
alkali cations by corona charging at high temperature. The hologram recorded in the glass plate is stable for more than 1
month at room temperature. After removal of the azobenzene polymer film from the plate, poly(methyl methacrylate) (PMMA) film
was spin-coated onto the plate. The hologram recorded in the plate was reconstructed with the same surface relief structure
on the PMMA film by corona charging again at 110°C. 相似文献
72.
73.
Yoshiro Hirai Takao Yamazaki Shun-ichi Hirokami Masanori Nagata 《Tetrahedron letters》1980,21(32):3067-3070
Upon irradiation, 4(3H)-pyrimidin-4-one(1) afforded a di-imine derivative(2) which, when hydrolyzed in an acidic methanol solution, gave N-methyl acetoacetamide(3). On the other hand, the fused 4(3H)-pyrimidin-4-ones, (4) and (5), gave medium-ring lactams(6) and (7), which were hydrolyzed in an acidic methanol solution to give (8) and (9), respectively. 相似文献
74.
Yotaro Morishima Toru Kitani Takaomi Kobayashi Yasuhiro Saeki Shun-ichi Nozakura Takeshi Ohno Shunji Kato 《Photochemistry and photobiology》1985,42(5):457-464
Abstract— Anionic polyelectrolytes functionalized with the 5-deazaflavin group (dFl) were synthesized. The lifetime of the triplet excited dFl in the polyelectrolytes with a 2-mol% dFl content (AdFl-2) was about 10 times longer than that of a low molecular weight analog (AdFl-M). 2-Mercaptoethanol (RSH) reduced the triplet dFl with the rate constant of k red = 2.01 × 108 M −1 s−1 for AdFl-M and k red = 4.4 × 107 M −1 s−1 for AdFl-2. A zwitterionic viologen (SPV) oxidized the triplet dFl with the rate constant of k red = 3.69 × 109 M −1 s−1 for AdFl-M and k ox = 7.4 × 108 M−1 s−1 for AdFl-2. The smaller rate constants for the polymer system were discussed in terms of the hindering effect of the macromolecular microenvironment. The back electron transfer was shown to be drastically slowed in the AdFl-2-SPV system as a result of the intensive electrostatic effect of the polyelectrolytes. The buildup of the viologen radicals was studied under the steady-state illumination of the three component systems including viologen and RSH. The dFl group was demonstrated to serve as a very efficient photosensitizer in the oxidative cycle in case back electron transfer was retarded. This is the case of the AdFl-2-SPV system which gave the quantum yield of about 0.4 for the SPV− buildup. By comparison, the AdFl-2-MV2 + system resulted in a much slower buildup of MV +radicals. 相似文献
75.
76.
77.
Oshige M Kawasaki S Takano H Yamaguchi K Kurita H Mizuno T Matsuura S Mizuno A Katsura S 《Journal of fluorescence》2011,21(3):1189-1194
Direct observation studies of single molecules have revealed molecular behaviors usually hidden in the ensemble and time-averaging
of bulk experiments. Direct single DNA molecule analysis of DNA metabolism reactions such as DNA replication, repair, and
recombination is necessary to fully understand these essential processes. Intercalation of fluorescent dyes such as YOYO-1
and SYTOX Orange has been the standard method for observing single molecules of double-stranded DNA (dsDNA), but effective
fluorescent dyes for observing single molecules of single-stranded DNA (ssDNA) have not been found. To facilitate direct single-molecule
observations of DNA metabolism reactions, it is necessary to establish methods for discriminating ssDNA and dsDNA. To observe
ssDNA directly, we prepared a fusion protein consisting of the 70 kDa DNA-binding domain of replication protein A and enhanced
yellow fluorescent protein (RPA-YFP). This fusion protein had ssDNA-binding activity. In our experiments, dsDNA was stained
by SYTOX Orange and ssDNA by RPA-YFP, and we succeeded in staining ssDNA and dsDNA by using RPA-YFP and SYTOX Orange simultaneously. 相似文献
78.
Abstract— Quenching of excited state of Ru(bpy)2 (poly-4-methyl-4'-vinyl-2,2'-bipyridine)Cl2 by sodium anthraquinone-2-sulfonate was found to be a static process. The quenching was interpreted by application of a modified Perrin model. Radius of the quenching sphere was estimated to correspond to 6.65 monomer units and was unchanged on varying the Ru2 + content of the polymer. Energy migration along the polymer chain was denied. 相似文献
79.
Jin Y Tonan K Ikawa S 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2002,58(12):2795-2802
Intramolecularly hydrogen-bonded structures of proline-containing model peptides with a sequence of N-tert-butoxycarbonyl-prolyl-Xaa-NHCH3 [Xaa = Gly (glycyl), Ala (alanyl), Phe (phenylalanyl), Leu (leucyl), Ile (isoleucyl), and Val (valyl)] were studied by proton nuclear magnetic resonance and infrared spectroscopy. Variation of chemical shifts of amide protons with composition change of DMSO-d6/CDCl3 mixed solvents were found to be a good measure of intramolecular hydrogen bonding of peptides in CDCl3 solution. It has been shown that 10- and 7-membered hydrogen-bonded rings, which should have the beta- and gamma-turn like structures in proteins, respectively, form competitively with each other. It is suggested that the equilibrium between the two hydrogen-bonded rings is determined by steric hindrance due to a side chain of the Xaa residue. Free energies for formation of the 10- and 7-membered hydrogen-bonded rings, deltaG10 and deltaG7, were estimated from the solvent composition-dependent change of the chemical shifts. A good correlation between deltaG10 and the occurrence frequencies of residues Xaa at the (i + 2)th position for the beta-turns in proteins has been found. 相似文献
80.
Yoshihiro Itoh Yotaro Morishima Shun-ichi Nozakura 《Photochemistry and photobiology》1984,39(4):451-457
Abstract— Fluorescence quenching of amphiphilic copolymers, poly(9-vinylphenanthrene-co-sodium 2-acrylamido-2-methylpropanesulfonate) (APh) and poly(9-vinylphenanthrene-co-3-methacrylamidopropyltrimethylammonium methyl sulfate) (QPh), in aqueous solution, was studied using methyl viologen (MV2+) or 4,4'-bipyridinium-1, 1'-bis(trimethylenesulfonate) (SPV) as oxidative quenchers. The fluorescence of the excited phenanthrene groups in APh was found to be efficiently quenched by MV2+. The apparent second-order rate constant for the quenching, kq, ranged in the magnitude of 1011 -1012M-1 s-1, which are well beyond the diffusion-controlled limit. This is presumably due to an increase of the effective concentration of MV2+ around the fluorophore in the copolymer resulting from electrostatic attraction between MV2+ and anionic segments of APh. This strong electrostatic interaction also favors the formation of ground-state EDA (electron donor acceptor) complex between the phenanthrene residue and MV2+. Such striking behaviors were not observed with the related model compound. Unexpectedly, the quenching with SPV, a zwitterionic quencher, was also enhanced in the polymer system (kq= 2–6 × 1010M-1 s-1), suggesting the presence of some attractive interaction between APh and SPV. Contrary to the APh system, the fluorescence quenching of the corresponding cationic polymer (QPh) with MV2+ was strongly diminished (kq= 5 × 108M-1 s-1). This indicates that the polycation of QPh effectively prevents the access of MV2+ to the polymer. 相似文献