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81.
Density functional theory (DFT) calculations at the B3LYP/6-31G(d) level demonstrated that sodium O-(3-phenylallyl) dithiocarbonate undergoes [3,3]-sigmatropic rearrangement to sodium S-(1-phenylallyl) dithiocarbonate, which then isomerizes to the more thermodynamically stable sodium S-(3-phenylallyl) dithiocarbonate. The calculations also showed that sodium 2-alkenyl trithiocarbonates and their esters are more labile towards the allylic rearrangement. 相似文献
82.
T Matsuno K Maruyama J Tsutsui 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2012,88(7):385-395
Following Part 1, a comparison of CO2 -emissions pathways between "zero-emissions stabilization (Z-stabilization)" and traditional stabilization is made under more realistic conditions that take into account the radiative forcings of other greenhouse gases and aerosols with the constraint that the temperature rise must not exceed 2 °C above the preindustrial level. It is shown that the findings in Part 1 on the merits of Z-stabilization hold under the more realistic conditions. The results clarify the scientific basis of the policy claim of 50% reduction of the world CO2 emissions by 2050. Since the highest greenhouse gas (GHG) concentration and temperature occur only temporarily in Z-stabilization pathways, we may slightly relax the upper limit of the temperature rise. We can then search for a scenario with larger emissions in the 21st century; such a scenario may have potential for practical application. It is suggested that in this Z-stabilization pathway, larger emissions in the near future may be important from a socioeconomic viewpoint.(Contributed by Taroh MATSUNO, M.J.A.). 相似文献
83.
Utsumi S Urita K Kanoh H Yudasaka M Suenaga K Iijima S Kaneko K 《The journal of physical chemistry. B》2006,110(14):7165-7170
A single-wall carbon nanohorn (SWNH) colloid was made to be magnetically responsive by anchoring magnetite nanoparticles prepared by the homogeneous mixing of FeCl(2)-FeCl(3) and NaOH solutions. Transmission electron microscopy observation showed the high dispersion of magnetite particles of 2-9 nm on the surface of the SWNH colloid, coinciding with the broad X-ray diffraction peaks of the magnetites. The magnetization measurements showed that the magnetite nanoparticles-anchored SWNH (mag-SWNH) colloid has the hybrid property of ferrimagnetism and superparamagnetism. It was demonstrated that mag-SWNH colloid dispersed in water by sonication responded to an external magnetic field, gathering toward a magnet. N(2) adsorption experiments showed the high nanoporosity of mag-SWNHs and that magnetite nanoparticles were preferably anchored at "nanowindow" sites and the entrance sites of interstitial pores. This magnetically responsive SWNH colloid should contribute to the field of drug delivery. 相似文献
84.
Shigeru Yamaguchi Hiroyuki Kobayashi Takuhito Narita Koki Kanehira Shuji Sonezaki Yoshinobu Kubota Shunsuke Terasaka Yoshinobu Iwasaki 《Photochemistry and photobiology》2010,86(4):964-971
Titanium dioxide (TiO2) is thought to be a photocatalytic agent excited by UV light. Our aim was to investigate the photocatalytic antitumor effect of water-dispersed TiO2 nanoparticles on C6 rat glioma cells and to evaluate the treatment responses by the spheroid models. Water-dispersed TiO2 nanoparticles were constructed by the adsorption of chemical modified polyethylene glycol (PEG) on the TiO2 surface (TiO2/PEG). Each monolayer and spheroid of C6 cells was coincubated with various concentrations of TiO2/PEG and subsequently irradiated with UV light. Damage of the cells and spheroids was evaluated sequentially by staining with the fluorescent dyes. The cytotoxic effect was correlated with the concentration of TiO2/PEG and the energy dose of UV irradiation. More than 90% of cells were killed after 13.5 J cm−2 of UV irradiation in the presence of 500 μg mL−1 TiO2/PEG. The irradiated spheroids in the presence of TiO2/PEG showed growth suppression compared with control groups. In TiO2/PEG-treated spheroids, the number of Annexin V-FITC-stained cells gradually increased during the first 6 h, and subsequently propidium iodide-stained cells appeared. The results of this study suggest that newly developed photoexcited TiO2/PEG have antitumoral activity. Photodynamic therapy utilizing this material can be a clue to a novel therapeutic strategy for glioma. 相似文献
85.
86.
The rotational process of 2-aryl ring in 1-acyl-2-aryl-3,3-dimethylindolines was determined by density functional theory (DFT) at B3LYP/6-31G(d) level. The calculated barrier height for the rotational process of [2-(2-hydroxynaphthalen-1-yl)-3,3-dimethylindolin-1-yl]phenylmethanone (1) was ca. 30 kcal/mol, comparable to the previously reported experimental values of 26–28 kcal/mol for the corresponding derivatives. The Hartree–Fock (HF) calculation overestimated the barrier. The DFT-calculated rotational barrier height provided valuable information for knowing whether the conformers were isolable or not. The transition structure analyses showed that the presence of 2,6-substituents on the aryl ring is essential for the isolation of the conformers at room temperature. Based on the DFT-calculated geometries, the rotational process and the intramolecular weak interactions in the restricted rotation were analyzed. 相似文献
87.
Kubozono Y Mitamura H Lee X He X Yamanari Y Takahashi Y Suzuki Y Kaji Y Eguchi R Akaike K Kambe T Okamoto H Fujiwara A Kato T Kosugi T Aoki H 《Physical chemistry chemical physics : PCCP》2011,13(37):16476-16493
New carbon-based superconductors are synthesized by intercalating metal atoms into the solid-phase hydrocarbons picene and coronene. The highest reported superconducting transition temperature, T(c), of a hydrocarbon superconductor is 18 K for K(3)picene. The physics and chemistry of the hydrocarbon superconductors are extensively described for A(x)picene (A: alkali and alkali earth-metal atoms) for x = 0-5. The theoretical picture of their electronic structure is also reviewed. Future prospects for hydrocarbon superconductors are discussed from the viewpoint of combining electronics with condensed-matter physics: modification of the physical properties of hydrocarbon solids is explored by building them into a field-effect transistor. The features of other carbon-based superconductors are compared to clarify the nature of hydrocarbon superconductors. 相似文献
88.
Hashimoto S Fujimori T Tanaka H Urita K Ohba T Kanoh H Itoh T Asai M Sakamoto H Niimura S Endo M Rodriguez-Reinoso F Kaneko K 《Journal of the American Chemical Society》2011,133(7):2022-2024
Vibrational-rotational properties of CH(4) adsorbed on the nanopores of single-wall carbon nanohorns (SWCNHs) at 105-140 K were investigated using IR spectroscopy. The difference vibrational-rotational bands of the ν(3) and ν(4) modes below 130 K show suppression of the P and R branches, while the Q branches remain. The widths of the Q branches are much narrower than in the bulk gas phase due to suppression of the Doppler effect. These results indicate that the rotation of CH(4) confined in the nanospaces of SWCNHs is highly restricted, resulting in a rigid assembly structure, which is an anomaly in contrast to that in the bulk liquid phase. 相似文献
89.
Density functional theory (DFT) calculations at the B3LYP/6-31G(d) and B3LYP/6-31G+(d) levels demonstrated that O-furfuryl S-alkyl dithiocarbonate (1) undergoes aromatic [3,3]-sigmatropic rearrangement to the energetically unfavorable S-(2-methylene-2,3-dihydrofuran-3-yl) S-alkyl dithiocarbonate (2'), which then rearranges to furfuryl alkyl sulfide (3) with COS extrusion to regain the aromaticity lost in the first step. 相似文献
90.
Masashi Eto Koki YamaguchiItaru Shinohara Fumikazu ItoYasuyuki Yoshitake Kazunobu Harano 《Tetrahedron》2011,67(38):7400-7405
(4-Nitrophenyl- and 4-chlorophenyl)(2-hydroxy-3,3-dimethylindolin-1-yl)methanone (4a,b) serve as clathrate hosts for benzene guests. X-ray crystal analyses of the inclusion compounds of 4a and 4b with benzene indicate that the ‘edge-to-face interaction’ plays an important role in the formation of the inclusion complexes with benzene as well as in the host-host interactions. PM6 molecular orbital calculations were found to reproduce the characteristic structural features of both intra- and intermolecular edge-to-face interactions. 相似文献