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排序方式: 共有98条查询结果,搜索用时 187 毫秒
91.
Jarmila Müllerová Marinus Fischer Marie Netrvalová Miro Zeman Pavel Šutta 《Central European Journal of Physics》2011,9(5):1301-1308
The effect of deposition temperature on the structural and optical properties of amorphous hydrogenated silicon (a-Si:H) thin
films deposited by plasma-enhanced chemical vapour deposition (PECVD) from silane diluted with hydrogen was under study. The
series of thin films deposited at the deposition temperatures of 50–200°C were inspected by XRD, Raman spectroscopy and UV
Vis spectrophotometry. All samples were found to be amorphous with no presence of the crystalline phase. Ordered silicon hydride
regions were proved by XRD. Raman measurement analysis substantiated the results received from XRD showing that with increasing
deposition temperature silicon-silicon bond-angle fluctuation decreases. The optical characterization based on transmittance
spectra in the visible region presented that the refractive index exhibits upward trend with increasing deposition temperature,
which can be caused by the densification of the amorphous network. We found out that the scale factor of the Tauc plot increases
with the deposition temperature. This behaviour can be attributed to the increasing ordering of silicon hydride regions. The
Tauc band gap energy, the iso-absorption value their difference were not particularly influenced by the deposition temperature.
Improvements of the microstructure of the Si amorphous network have been deduced from the analysis. 相似文献
92.
Imramovsky A Pesko M Kralova K Vejsova M Stolarikova J Vinsova J Jampilek J 《Molecules (Basel, Switzerland)》2011,16(3):2414-2430
In this study, a series of twenty-two 5-chloro-2-hydroxy-N-[2-(arylamino)-1-alkyl-2-oxoethyl]benzamides and ten 4-chloro-2-hydroxy-N-[2-(arylamino)-1-alkyl-2-oxoethyl]benzamides is described. The compounds were analyzed using RP-HPLC to determine lipophilicity. Primary in vitro screening of the synthesized compounds was performed against mycobacterial, bacterial and fungal strains. They were also evaluated for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. The compounds showed biological activity comparable with or higher than the standards isoniazid, fluconazole, penicillin G or ciprofloxacin. For all the compounds, the relationships between the lipophilicity and the chemical structure of the studied compounds as well as their structure-activity relationships are discussed. 相似文献
93.
In this study, laccase (from Trametes versicolor, 8.3 U mg enz ?1 ) was used for the decolorisation of Saturn Blue L4G (10 mg L?1). The efficiency of the decolorisation (ratio between the amount of decolorised dye and initial amount of dye) by a free enzyme was 48 % and the decolorisation rate was determined at 2.11 × 10?3 mgdye mg enz ?1 min?1. After immobilisation in lens-shaped poly(vinyl alcohol) hydrogel capsules LentiKats® Biocatalyst (LB) (concentration of immobilised enzyme: 4 mg per g of particles; volume-loading rate of LB: 10 g per 100 mL of medium), the enzyme retained 16.1 % of its original activity (1.34 U mg enz ?1 ). Immobilised laccase was used for the dye decolorisation in 130 repeated batch tests with 71 % efficiency (LB activity: 7 × 10?3 mgdye min?1 g LB ?1 ). In continuous mode (after 716.5 h), the efficiency of the dye decolorisation was 48 % (LB activity: 3.3 × 10?4 mgdye min/?1 g LB ?1 ). 相似文献
94.
Bríza T Kejík Z Císarová I Králová J Martásek P Král V 《Chemical communications (Cambridge, England)》2008,(16):1901-1903
Polymethinium salts based on substituted malondialdehyde have been prepared; the salt with PEG substitution showed high selectivity for sulfate anions and heparin in aqueous medium at physiological condition; intracellular imaging of heparin-rich subcellular compartments was achieved with our polymethinium novel receptor for cancer cell lines. 相似文献
95.
Králová J Koivukorpi J Kejík Z Poucková P Sievänen E Kolehmainen E Král V 《Organic & biomolecular chemistry》2008,6(9):1548-1552
This paper describes the preparation and use of conjugates of porphyrins and bile acids as ligands to bind to tumor expressed saccharides. Bile acid-porphyrin conjugates were tested for recognition of saccharides that are typically present on malignant tumor cells. Fluorescence microscopy, in vitro PDT cell killing, and PDT of subcutaneous 4T1 mouse tumors is reported. High selectivity for saccharide cancer markers and cancer cells was observed. This in vivo and in vitro study demonstrated high potential use for these compounds in targeted photodynamic therapy. 相似文献
96.
97.
A series of eighteen novel esters of salicylanilides with benzenesulfonic acid were designed, synthesized and characterized by IR, 1H-NMR and 13C-NMR. They were evaluated in vitro as potential antimycobacterial agents towards Mycobacterium tuberculosis, Mycobacterium avium and two strains of Mycobacterium kansasii. In general, the minimum inhibitory concentrations range from 1 to 500 μmol/L. The most active compound against M. tuberculosis was 4-chloro-2-(4-(trifluoromethyl)phenylcarbamoyl)-phenyl benzenesulfonate, with MIC of 1 μmol/L and towards M. kansasii its isomer 5-chloro-2-(4-(trifluoromethyl)phenylcarbamoyl)phenyl benzenesulfonate (MIC of 2-4 μmol/L). M. avium was the less susceptible strain. However, generally, salicylanilide benzenesulfonates did not surpass the activity of other salicylanilide esters with carboxylic acids. 相似文献
98.