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81.
Yasumasa Hirashima 《Topology and its Applications》2007,154(12):2412-2424
Pairings and copairings of topological spaces induce pairings of function spaces. These induced pairings of function spaces are studied. For this purpose, the C-open topology of function spaces is studied for subcategories C of Top. It is shown that the C-open topology enjoys good properties for homotopy theory. Making use of the C-open topology, theory of induced pairings is established and fundamental results on pairings which deduce various commutativity properties of elements in homotopy set are extended to function spaces. 相似文献
82.
83.
Shin-ichi Hirashima 《Tetrahedron》2006,62(33):7887-7891
Alcohols were found to be oxidized to the corresponding carboxylic acid in the presence of a catalytic inorganic bromo source, for example, lithium bromide, bromine, and hydrobromic acid, under photo-irradiation. 相似文献
84.
Sakurai T Tashiro K Honsho Y Saeki A Seki S Osuka A Muranaka A Uchiyama M Kim J Ha S Kato K Takata M Aida T 《Journal of the American Chemical Society》2011,133(17):6537-6540
Novel liquid crystalline (LC) semiconductors were prepared from the copper complex of a fused porphyrin dimer as the electroactive core by attaching to its periphery dodecyl and semifluoroalkyl side chains site-specifically (P≡P(hetero)) and semifluoroalkyl side chains alone (P≡P(homo)). The former and latter formed rectangular columnar and orthorhombic LC mesophases, respectively, where the stacking geometries of the π-conjugated core are quite different from one another. Although the π-electronic properties of the core units in P≡P(hetero) and P≡P(homo) in solution are substantially identical to one another, transient photocurrent profiles of their LC states under time-of-flight conditions clearly showed that P≡P(hetero) behaves as an n-type semiconductor, whereas P≡P(homo), in contrast, behaves as a p-type semiconductor. 相似文献
85.
Tahara K Sakai T Yamamoto H Takeuchi H Hirashima N Kawashima Y 《Chemical & pharmaceutical bulletin》2011,59(3):298-301
This study sought to evaluate the in vitro transfection efficiency of plasmid DNA (pDNA)-loaded chitosan-modified poly(DL-lactide-co-glycolide) nanospheres (CS-PLGA NS) in a gene-delivery system. Using the emulsion solvent diffusion (ESD) method, pDNA-loaded PLGA NS was prepared and the surface of the PLGA NS was modified by binding to CS. Gene transfection ability of CS-PLGA NS was examined in A549 cells. The luciferase gene was used as a reporter gene. The pattern of luciferase activity by pDNA-loaded CS-PLGA NS was initially weak, but gradually grew stronger before decreasing activity. These phenomena should be in accordance with the sustained-release profile of pDNA from PLGA NS in the cytosol and the pDNA protection against DNase. Positively charged CS-PLGA NS was found, by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay, not to exhibit cytotoxicity on A549 cells. These results suggest that CS-PLGA NS are potential contributors to efficient pDNA delivery due to their increased interactions with cells and lack of cytotoxic effects. 相似文献
86.
Yasumasa Hirashima 《Topology and its Applications》2011,158(3):445-456
Topologies on base point preserving function spaces are studied making use of the Brown-Booth-Tillotson C-smash product and the topologies on function spaces defined by the classes C of exponentiable spaces. Some conditions on the classes C are obtained for exponential bijections and exponential homeomorphisms in the category of topological spaces with base point. Conditions for exponential homeomorphisms are obtained for CW-complexes whose cellular structure implies precise results. 相似文献
87.
Tanaka S Yagyu A Kikugawa M Ohashi M Yamagata T Mashima K 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(13):3693-3709
Four different types of square‐planar Pt4 clusters, trans‐[Pt4(μ‐OCOCH3)6(μ‐ArNCHNAr)2] ( 2 : ArNCHNAr=N,N′‐diarylformamidinate), [Pt4(μ‐OCOCH3)7(μ‐ArNCHNAr)] ( 8 ), cis‐[Pt4(μ‐OCOCH3)6(κ4‐N4‐DArBp)] ( 9 : DArBp=1,3‐bis(arylbenzamidinate)propane), and [Pt4Cl2(μ‐OCOCH3)5(κ4‐N2,P2‐dpfam)] ( 13 : dpfam=N,N′‐bis[(2‐diphenylphosphino)phenyl]formamidinate), were successfully prepared by using selective substitution reactions of in‐plane acetate ligands of [Pt4(μ‐OCOCH3)8] ( 1 ), which has four in‐plane and four out‐plane acetate ligands, with appropriate capping ligands. Fundamental substitution reactions of the remaining in‐plane acetates with benzoic acid derivatives were also investigated. All newly prepared complexes were characterized from spectral and physical data and combustion analysis. X‐ray crystallographic studies of some of the clusters were also performed. Electrochemical measurements of amidinate‐modified Pt4 clusters revealed stepwise oxidation processes of the Pt4 core due to Pt49+/Pt48+ and Pt410+/Pt49+. Based on the lability of the in‐plane acetate ligands of the modified Pt4 clusters, reactions of cis‐[Pt4(μ‐OCOCH3)6(κ4‐N4‐DArBp)] ( 9 c : Ar=C6H4tBu‐4) with ferrocenedicarboxylic acid and p‐phenylenedipropionic acid resulted in the selective formation of cyclic dimers 17 and 18 and the reaction of 13 with 4,4′‐biphenyldicarboxylic acid afforded a linear dimer 20 . The dimers were characterized by spectral data, as well as X‐ray analyses for 17 and 18 . The finding of two Fe3+/Fe2+ redox couples in the electrochemical measurement of dimer 17 indicated that two ferrocenyl units in dimer 17 communicated electronically. 相似文献
88.
Hiroshi Akutsu Kosuke Nakashima Shin-ichi Hirashima Hikari Matsumoto Yuji Koseki Tsuyoshi Miura 《Tetrahedron》2019,75(16):2431-2435
The asymmetric direct bisvinylogous conjugate addition of 5-benzylfurfural derivatives to nitroalkenes using a thiourea organocatalyst resulted in a corresponding ε-regioselective addition products in high yields and up to 95% enantiomeric excess. 相似文献
89.
Shingo Hirashima Dr. Ji Hoon Han Hitomi Tsuno Yusuke Tanigaki Dr. Soyoung Park Prof. Dr. Hiroshi Sugiyama 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(42):9913-9919
Here, the synthesis, photophysical characterization, and application of a new size-expanded thymine nucleoside, diox T , is described. diox T has desirable qualities as a T surrogate, including excellent quantum yield (0.36) and high environmental sensitivity. When incorporated into single- and double-stranded DNA, diox T showed excellent photophysical characteristics including a high quantum yield (average 0.20), and unlike BgQ, demonstrated dependence on neighboring bases without significant destabilization of the duplex. Interestingly, the matched base pair of adenine (A) and diox T has the unique property that it exhibits higher fluorescence than mismatched base pairs, and diox T has self-quenching effects. As one example of the possible applications of these promising features, single nucleoside polymorphism typing is demonstrated for discrimination of A by using diox T . The results suggest that diox T can be used for a broad range of applications in chemical biology. 相似文献
90.
Hironobu Iwabuchi Tsuneaki Suzuki 《Journal of Quantitative Spectroscopy & Radiative Transfer》2009,110(17):1926-1939
The phase function for solar light scattering by large particles such as cloud droplets is strongly anisotropic due to very strong peaking in the forward direction. This creates numerical difficulties when attempting to calculate accurate reflected and transmitted radiances, which are important for remote sensing of atmospheric and surface properties. A popular approach uses the delta function to approximate the forward-scattering peak in a fraction of energy and a limited number of polynomial terms or a geometrically truncated function for the remaining fraction (so-called truncation approximations). This article compares and discusses several methods for fast and accurate calculations using truncation approximations. When using a single truncation approximation for all scattering orders, large biases appear in directions near the solar and anti-solar points. As shown here, high accuracy can be obtained using different truncation approximations depending on the order of scattering. Of particular importance is the use of phase functions close to the exact phase functions for the first few orders of scattering. Applying the method in combination with the Monte Carlo (MC) method, in which the truncation fraction for a scattering order depends on the scattering angle at the previous scattering event, obtains accurate radiance calculations under almost all geometrical and optical conditions, including in directions near the solar point. Because the method also reduces computational noise due to the MC sampling of radiance, it is useful for fast and accurate radiance calculations for cloudy atmospheres. 相似文献