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81.
Evgeniy M. Chistyakov Sergey N. Filatov Pavel A. Yudaev Vyacheslav V. Kireev 《Tetrahedron letters》2019,60(5):444-448
4-(2-(4-((β-Methallyl)oxy)phenyl)propan-2-yl)phenol was prepared via the reaction of methallyl chloride with bisphenol A and used for the synthesis of hexakis-4-(2-(4-((β-methallyl)oxy)phenyl)propan-2-yl)phenoxycyclotriphosphazene. It was revealed that the latter undergoes the Claisen rearrangement and can be also epoxidized by 3-chloroperbenzoic acid. The obtained epoxide was cured by a treatment with isophorone diamine. The decomposition and glass transition temperatures of cured resin were also estimated (275 and 130?°C, respectively) by DSC and TGA methods. 相似文献
82.
Agafonova IG Radchenko OS Novikov VL Aminin DL Stonik VA 《Magnetic resonance imaging》2008,26(6):763-769
The anticancer effect of thiacarpine, a synthetic analogue of the known cytotoxic alkaloid polycarpine isolated from the Pacific ascidian Polycarpa aurata, was investigated in vivo in experiments using mouse solid Ehrlich carcinoma tumor as the target. A high-resolution magnetic resonance imaging (MRI) technique using a MR tomograph "PharmaScan" US70/16 (Bruker, Ettlingen, Germany) was used for visualization and quantification of tumor size. Fluorescence microscopy and image analysis were applied to determine Ehrlich carcinoma cell chromatin condensing (apoptosis) and necrosis in Ehrlich carcinoma cells at the action of thiacarpine in in vitro experiments. The scan and size calculations of the tumor and some mouse organs were carried out during the experiments. Thiacarpine in a total dose of 100 mg/kg was found to exhibit the delay in growth of the mouse tumor. The antineoplastic effect of this compound was accompanied by an increase in the lifetime of experimental mice in comparison with the control group of animals. Our data show that the ability of thiacarpine to induce apoptosis in carcinoma cells may contribute to thiacarpine anticancer effects against mice solid Ehrlich carcinoma in vivo detected by MRI. 相似文献
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86.
Olga A. Kraevaya Alexander S. Peregudov Vyacheslav M. Martynenko Pavel A. Troshin 《Tetrahedron letters》2018,59(7):605-607
The chlorofullerene C60Cl6 was demonstrated as a versatile precursor for the synthesis of two isomerically pure fullerenols via tetrabutylammonium bromide promoted reactions with water. Performing the synthesis in wet chlorobenzene produced 1,4-C60(OH)2 as the only isolable product along with substantial amounts of non-functionalized C60. However, the addition of DMSO as a co-solvent altered the reaction pathway, leading to the formation of C60(OH)5Br as the main product. Both isolated compounds were novel and their molecular compositions and structures were confirmed by mass spectrometry and NMR spectroscopy. The fullerenol C60(OH)5Br, which was formed in a moderate yield, represents the first isomerically pure polyhydroxylated fullerene available on a large scale. 相似文献
87.
Calculation of solvation free energies of charged solutes using mixed cluster/continuum models 总被引:2,自引:0,他引:2
We derive a consistent approach for predicting the solvation free energies of charged solutes in the presence of implicit and explicit solvents. We find that some published methodologies make systematic errors in the computed free energies because of the incorrect accounting of the standard state corrections for water molecules or water clusters present in the thermodynamic cycle. This problem can be avoided by using the same standard state for each species involved in the reaction under consideration. We analyze two different thermodynamic cycles for calculating the solvation free energies of ionic solutes: (1) the cluster cycle with an n water cluster as a reagent and (2) the monomer cycle with n distinct water molecules as reagents. The use of the cluster cycle gives solvation free energies that are in excellent agreement with the experimental values obtained from studies of ion-water clusters. The mean absolute errors are 0.8 kcal/mol for H(+) and 2.0 kcal/mol for Cu(2+). Conversely, calculations using the monomer cycle lead to mean absolute errors that are >10 kcal/mol for H(+) and >30 kcal/mol for Cu(2+). The presence of hydrogen-bonded clusters of similar size on the left- and right-hand sides of the reaction cycle results in the cancellation of the systematic errors in the calculated free energies. Using the cluster cycle with 1 solvation shell leads to errors of 5 kcal/mol for H(+) (6 waters) and 27 kcal/mol for Cu(2+) (6 waters), whereas using 2 solvation shells leads to accuracies of 2 kcal/mol for Cu(2+) (18 waters) and 1 kcal/mol for H(+) (10 waters). 相似文献
88.
Fleshker S Preise D Kalchenko V Scherz A Salomon Y 《Photochemistry and photobiology》2008,84(5):1231-1237
Abstract This study hypothesized that success rate assessment of vascular targeted photodynamic therapy (VTP) of solid tumors 24 h post-treatment may allow prompt administration of a second treatment in case of failure, increasing the overall success rate. Here, we show that treatment of luciferase transfected CT26-luc mouse colon carcinoma tumors in BALB/c mice by VTP with WST11 (a Pd-bacteriochlorophyll-based photosensitizer) allows fast assessment of treatment success 24 h post-treatment, using bioluminescence imaging (BLI). WST11-VTP was found to abolish luciferin bioluminescence in the treated tumors resulting in two types of responses. One, comprising 75% of the mice, signified successful outcome, presenting neither BLI signal nor tumor regrowth (24 h-90 days post-VTP). The second (the remaining 25% of the mice) signified treatment failure, presenting various levels of BLI signal with subsequent tumor regrowth (24 h-90 days). Consequently, the mice that failed the first treatment were treated again. We show that treatment success rate in both VTP sessions was identical and that the cumulative success rate of the treatment increased from 75% to over 90%. These results therefore, present a fast method of assessing VTP outcome and support the feasibility of successive multiple treatments with these sensitizers in the clinical arena. The presented methodology can also be helpful in future preclinical studies, and expedite the development of VTP drugs. 相似文献
89.
Perfluoro-2-ethyl-2-phenylbenzocyclobutenone heated with SbF5 at 70 °C and then treated with water, forms perfluoro-3-ethyl-3-phenylphthalide. In contrast to this, heating of perfluoro-2,2-diethylbenzo-cyclobutenone with SbF5 at 70 °C gives, after treatment of the reaction mixture with water, perfluoro-2-(pent-2-en-3-yl)benzoic acid. When the reaction temperature is raised to 125 °C, a solution of a salt of perfluoro-4-ethyl-3-methylisochromenyl cation is obtained. Hydrolysis of the solution of the salt gives perfluoro-4-ethyl-3-methylisochromen-1-one. 相似文献
90.
Diev VV Stetsenko ON Tung TQ Kopf J Kostikov RR Molchanov AP 《The Journal of organic chemistry》2008,73(6):2396-2399
1,3-Dipolar cycloaddition of C-aryl,N-aryl (or N-methyl) nitrones with a number of 1,2-diphenylcyclopropenes substituted at the C(3) position occurs with the formation of expected "normal" cycloadducts (with N-methylnitrones) and products of their subsequent transformations. Among them are corresponding alpha-acetophenyl aziridines and tetra (or penta) -arylpyrroles. Aziridines and the normal cycloadducts can be also thermally converted to such arylpyrroles with moderate to good yields. Substitution at the C(3( position of cyclopropenes by an electron acceptor group decreases the reactivity of cyclopropenes. 相似文献