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91.
Reaction of dibenzoylmethane with (diacetoxyiodo)benzene in the presence of KOH in MeCN quantitatively gave the corresponding iodonium ylide, which was treated with a HF reagent to afford the corresponding 2-fluorinated dibenzoylmethane in 14-50% yields. The similar reaction of the iodonium ylides obtained from 1-phenylbutan-1,3-dione, ethyl benzoylacetate, and ethyl p-nitrobenzoylacetate with TEA·3HF gave the corresponding fluorinated products in 17-34% yields. It is suggested that the fluorinated products were formed through the C-protonation of the ylide, followed by displacement with fluoride ion. The same reaction of the iodonium ylide of dibenzoylmethane with concentrated HCl gave the corresponding chlorinated product in 45% yield. 相似文献
92.
Ejima H Matsumiya K Sawada T Serizawa T 《Chemical communications (Cambridge, England)》2011,47(27):7707-7709
A peptide aptamer, which was originally identified by affinity screening for hyperbranched poly(phenylene vinylene) (hypPPV), functioned as an excellent dispersant for hypPPV nanoparticle formation. 相似文献
93.
Hui Li Jinshu Wang Hongyi Li Shu Yin Tsugio Sato 《Research on Chemical Intermediates》2010,36(1):27-37
Nitrogen and sulfur co-doped mesoporous TiO2 thin films were fabricated using thiourea as a doping resource by the combination of the sol–gel and evaporation-induced
self-assembly (EISA) processes. Scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy
(XPS), N2 adsorption–desorption, and UV–vis spectra were performed to characterize the as-synthesized mesoporous TiO2 materials. The XPS result shows that O–Ti–N and O–Ti–S bonds in the (S, N)-codoped mesoporous TiO2 were formed. The resultant mesoporous (S, N)-codoped TiO2 exhibited anatase framework with a high porosity and a narrow pore distribution. After being illuminated for 3 h, methyl
orange (MO) could be degraded completely by the co-doped sample under the ultraviolet irradiation, whereas mesoporous TiO2 film without doping could only degrade 60% MO. After being illuminated by visible light, the water contact angles of the
mesoporous co-doped TiO2 samples decreased slightly, but the pure TiO2 mesoporous film exhibited no change in the hydrophilicity. 相似文献
94.
Nitrogen-doped titania was coupled with the commercial titania nanoparticles by mechanical milling in liquid medium. The as-prepared
nanocomposites (TiO2/TiO2−x
N
y
) were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) specific surface area, UV–Vis spectroscopy,
chemiluminescence, and acetaldehyde decomposition activity techniques. When a small amount of nitrogen-doped titania was added
into the commercial titania, higher intensity and longer lifetime of 1O2 was observed, and the photocatalytic activity was efficiently improved. The TiO2−x
N
y
acts as the acceptor of photoinduced holes. The recombination of the electron-hole was effectively depressed by the heterogeneous
electron transfer. This could be an effective way to obtain highly active photocatalysts. 相似文献
95.
Guo C Yin S Huang Y Dong Q Sato T 《Langmuir : the ACS journal of surfaces and colloids》2011,27(19):12172-12178
W(18)O(49) nanorods were synthesized by pyrolyzing (NH(4))(x)WO(3+x/2) nanorods precursors, which were prepared by a hydrothermal reaction using sulfate as a structure-directing agent, in a reductive atmosphere of H(2)(5 vol %)/N(2) at 500 °C for 1 h. W(18)O(49) nanorods showed high transmittance in the visible region as well as excellent shielding properties of NIR lights. A simulated experiment revealed that excellent heat insulating performance can be realized by applying a 70% visible light transparent W(18)O(49) coating on a quartz glass. Meanwhile, the W(18)O(49) nanorods also showed strong absorption of NIR light and instantaneous conversion of photoenergy to heat. In a word, W(18)O(49) nanorods hold interesting optical properties and are a promising material in a wide range of applications. 相似文献
96.
By a hydrothermal method, iron and nitrogen co-doped TiO2 and iron oxide impregnated nitrogen-doped TiO2 were prepared. The obtained Fe and N co-doped TiO2 showed mixed anatase, rutile, and brookite phases, and high specific surface areas above 160 m2/g. The Fe co-doping was proved to be effective to enhance the visible light absorption ability; however, the photocatalytic activity in deNO x experiment decreased due to the increase in the amount of lattice vacancy. On the other hand, the photocatalytic activity of N-doped TiO2 was improved by the impregnation of iron oxide. 相似文献
97.
M. Takahashi T. Hatano T. Ejima Y. Kondo K. Saito M. Watanabe T. Kinugawa J. H. D. Eland 《Journal of Electron Spectroscopy and Related Phenomena》2003,130(1-3):79-84
The use of photoelectron angular distributions to determine the linear polarization of VUV light over a wide range of photon energies is demonstrated. Light at wavelengths from 256 to 736 Å, partially polarized by large angle reflections in a toroidal grating monochromator and at a refocus mirror, has been analyzed. The results are validated by comparison measurements at spot wavelengths using multilayer polarizers. 相似文献
98.
Masataka Nishikawa Tsugio Mizoguchi Yukiko Dokiya Shinichi Bessho Hiroki Haraguchi 《International journal of environmental analytical chemistry》2013,93(4):591-598
Abstract The concentration of mercury in airborne particles was determined in samples collected at heights of 1m and at 175m up the Meteorological Observation Tower (213m) at the Meteorological Research Institute, Tsukuba between August 1985 and April 1986. The concentrations of particulate mercury at the two heights were compared with gaseous mercury levels at a height of 10m and with other chemical components in the particles. The concentrations of particulate mercury at both heights showed no positive correlation with those of gaseous mercury, total suspended particles, sulfate, chloride, sodium or calcium. However, there was some positive correlation between particulate mercury and nitrate concentrations especially at 175m; the concentrations of these components were found to be high when the wind direction was southwesterly. These results suggest that these components were transported from the Tokyo Metropolitan area. 相似文献
99.
100.