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81.
We have designed a second-generation TASC (target-assisted self-cleavage) probe. It is based on the switching-on of incorporated cis-acting DNAzyme activity upon the target-induced conformational change of the otherwise inactive off-target probes locked in an intrastrand base-paired hairpin geometry. With E. coli 16S ribosomal RNA-relevant oligonucleotides as targets, the locked TASC probe exhibits an allosteric factor of k(on)/k(off) = 65 and the sequence selectivity is high, in terms of single nucleotide difference, when particular sequence and length of targets are chosen. Preliminary experiments with fixed E. coli cells show that the locked TASC probe with a FRET pair can be used to image fixed E. coli cells. 相似文献
82.
The influence of fluoride (F(-)), bromide (Br(-)), iodide (I(-)), thiocyanate (SCN(-)) and nitrite (NO(2)(-)) on the reaction of a myeloperoxidase-H(2)O(2)-Cl(-) system with a nucleoside mixture was studied. The reaction was carried out under mildly acidic conditions and terminated by N-acetylcysteine. Without the additional anions, quantity of nucleosides consumed fell in the following order: 2'-deoxyguanosine>2'-deoxycytidine>2'-deoxythymidine>2'-deoxyadenosine asymptotically equal to 0. F(-) did not affect the reaction. Br(-) increased the consumption of 2'-deoxycytidine and 2'-deoxythymidine, but decreased that of 2'-deoxyguanosine. I(-), SCN(-) and NO(2)(-) suppressed the reaction. These results suggest that Br(-) has a unique effect in relation to nucleoside damage caused by myeloperoxidase. 相似文献
83.
Preparation of visible-light-responsive TiO2-xNx photocatalyst by a sol-gel method: analysis of the active center on TiO2 that reacts with NH3 总被引:5,自引:0,他引:5
Kuroda Y Mori T Yagi K Makihata N Kawahara Y Nagao M Kittaka S 《Langmuir : the ACS journal of surfaces and colloids》2005,21(17):8026-8034
Active reaction centers for ammonia on titanium oxyhydroxide were explored to direct the search for an efficient sol-gel method for the synthesis of a titanium oxynitride (TiO2-xNx) sample with an efficient responsiveness to the visible light constituting a main part of the solar spectrum. The results lead to the conclusion that the site giving IR bands at around 2195 cm(-1) for the adsorbed CO molecules at 300 K is a reactive site and behaves as Lewis acid site in the coordination environment of distorted five-coordinate Ti4+ ions. Ammonia molecules are adsorbed on such a site to form -NH2 and -OH species during the heat treatments at a temperature above 373 K, and they are ultimately incorporated into the TiO2 lattice as nitride through the dehydration at higher temperatures of up to 723 K, resulting in the formation of an anatase type of TiO2-xNx. 相似文献
84.
Yoshiro Kobayashi Toshinori Yamashita Katsuhiro Takahashi Hisashi Kuroda Itsumaro Kumadaki 《Tetrahedron letters》1982,23(3):343-344
Aryltrifluoromethylacetylenes were synthesized by an intramolecular Wittig reaction of trifluoroacetylarylidenephosphoranes, which were synthesized from arylmethyl halides. 相似文献
85.
Toshinori Saito Norio Saheki Minoru Hatanaka Toshiyasu Ishimaru 《Journal of heterocyclic chemistry》1983,20(1):73-75
1,3,4-Thiadiazol-2-ylacetic acids 4 were prepared by lithiation of 2-methyl-1,3,4-thiadiazoles 1 , followed by treatment with carbon dioxide. Diethyl 1,3,4-thiadiazol-2-ylmalonates 6 were prepared by nucleophilic displacement reaction of the corresponding bromides 5 with diethyl malonate. Introduction of the amino group at the a-position of 4 or 6 was carried out via oximation or bromination to give the amino ester 9 or 4 . Attempts to prepare DL-α-amino-1,3,4-thiadiazol-2-ylacetic acids from 9 or 4 were unsuccessful because the amino acids were decarboxylated too rapidly to be isolated in the free form. 相似文献
86.
A photocatalytic membrane reactor for VOC decomposition using Pt-modified titanium oxide porous membranes 总被引:1,自引:0,他引:1
Toshinori Tsuru Takehiro Kan-no Tomohisa Yoshioka Masashi Asaeda 《Journal of membrane science》2006,280(1-2):156-162
Porous titanium oxide membranes with pore sizes in the range of 2.5–22 nm were prepared by a sol–gel procedure, and were applied for decomposition of methanol and ethanol as model volatile organic compounds (VOCs) in a photocatalytic membrane reactor, where oxidation reaction occurs both on the surface and inside the porous TiO2 membrane while reactants are permeating via one-pass flow. Methanol was completely photo-oxidized by black-light irradiation to CO2 when methanol at a concentration of 100 ppm was used at a feed flow rate of 500 × 10−6 m3/min, but the conversion decreased when the MeOH concentration in the feed was increased. Pt-modification was carried out by photo-deposition, and led to a decrease in pore diameter. Using Pt-modified membranes, a nearly complete oxidation of methanol up to 10,000 ppm at a feed flow rate of 500 × 10−6 m3/min was observed. Thus, such membranes would be effective for purifying a permeate stream after one-pass permeation through the TiO2 membranes. The decomposition of ethanol is also discussed. 相似文献
87.
Takeshi Hoshikawa Xinming Huang Satoshi Uda Toshinori Taishi 《Journal of Crystal Growth》2006,290(2):338-340
Segregation phenomenon of Ga in Czochralski (CZ)–Si crystal growth has been investigated. The effective segregation coefficient, keff, of Ga was obtained for different growth rates by assuming the simple relationship between the concentration of Ga in Si crystal and the bulk Ga concentration in melt. Applying BPS theory to effective segregation coefficients which is valid for the melt-solidified fraction up to 0.38, an equilibrium segregation coefficient of Ga was obtained, k0=0.0079. 相似文献
88.
89.
Optical thin films are used in many optical elements; however, light scattering can be problematic. We investigate the effect of substrate surface roughness on the light scattering of optical thin films. The substrates are classified according to their surface roughness, from fine to very rough, and coated with a single TiO2 layer or a SiO2/TiO2 multilayer. The light scattering intensity increases as the substrate roughness increases. Scanning electron microscopy reveals that the number of nodules formed in the optical thin films increases with the substrate roughness, which affects the light scattering properties. 相似文献
90.
Germanium (Ge) single crystals with an extremely low density of grown-in dislocations were grown by the Czochralski (CZ) technique with boron oxide (B2O3) liquid. Because attachment of particles floating on the melt surface to a growing Ge crystal leads to generation of dislocations during the growth, partial covering of the Ge melt surface with B2O3 liquid was attempted. Such attachment of particles was drastically suppressed or the particles were caught by the introduction of B2O3 liquid, and a particle-free Ge melt was realized in the central region of the melt surface. Ge single crystals were successfully grown from such melt, the grown-in dislocation density being 0–1×103 cm−2, which was remarkably lower than that in Ge crystals grown by a conventional CZ technique. The contaminations by B and O atoms of the grown crystal detected by SIMS analysis were very low. These Ge crystals have the potential for application to be applied as high-quality, dislocation-free substrates of GaAs solar cells for various usages including in space. 相似文献