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71.
72.
Américo Lemos Marta Lopes 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2882-2890
Transient azovinylphosphonates, generated in situ by base induced dehydrohalogenation of the corresponding 2-bromo- and 2-chloro-acetylphosphonate- tertbutoxycarbonyl hydrazones are intercepted by electron rich alkenes and heterocycles in hetero Diels-Alder reactions, producing tetrahydopyridazine-3-phosphonates or open chain α-hydrazono phosphonates. 相似文献
73.
Dr. Frédéric Aribot Amélie Merle Dr. Pierre Dechambenoit Dr. Harald Bock Dr. Albert Artigas Dr. Nicolas Vanthuyne Dr. Yannick Carissan Dr. Denis Hagebaum-Reignier Dr. Yoann Coquerel Dr. Fabien Durola 《Angewandte Chemie (International ed. in English)》2023,62(28):e202304058
A rigid propeller-shaped conjugated triple macrocycle consisting of two nearly perfectly stacked benzene rings and three linking [5]helicene moieties has been synthesized using a glyoxylic Perkin approach. Analysis of the electron delocalization in this atypical aromatic molecule revealed global aromaticity and a 78 π-electron circuit along the edge of its triple loop, to the detriment of the two 6 π-electron circuits in the two stacked benzene rings. 相似文献
74.
Ryckebusch A Gilleron P Millet R Houssin R Lemoine A Pommery N Grellier P Sergheraert C Hénichart JP 《Chemical & pharmaceutical bulletin》2005,53(10):1324-1326
Protein farnesyltransferase of Plasmodium falciparum is a potential target in the treatment of malaria for which increased drug resistance is observed. The design, synthesis and evaluation of a series of N-(4-piperidinyl)benzamides is reported. The most potent compounds showed in vitro activity against the parasite at submicromolar concentrations. 相似文献
75.
In this work we study decompositions of para-complex and para-holomorphic vector-bundles endowed with a connection ? over a para-complex manifold. First we obtain results on the connections induced on the subbundles, their second fundamental forms and their curvature tensors. In particular we analyze para-holomorphic decompositions. Then we introduce the notion of para-complex affine immersions and apply the above results to obtain existence and uniqueness theorems for para-complex affine immersions. This is a generalization of the results obtained by Abe and Kurosu [AK] to para-complex geometry. Further we prove that any connection with vanishing (0, 2)-curvature, with respect to the grading defined by the para-complex structure, induces a unique para-holomorphic structure. 相似文献
76.
Barrie M. Baker Amândio Pereira Baía 《The Journal of the Operational Research Society》1995,46(6):698-707
A problem put forward recently by a Regional Water Authority differs from the well-known Capacitated Warehouse Location Problem only in that there are both weeks of normal demand levels and weeks of peak demand levels. We describe how Lagrangian relaxation based branch-and-bound algorithms have been adapted for the new problem. Computational results are given, enabling a comparison of the different approaches tried. 相似文献
77.
Bourderioux A Bénéteau V Mérour JY Baldeyrou B Ballot C Lansiaux A Bailly C Le Guével R Guillouzo C Routier S 《Organic & biomolecular chemistry》2008,6(12):2108-2117
We report the synthesis and biological evaluation of new oxophenylarcyriaflavins designed as potential anticancer agents. An efficient synthesis involving palladium-catalyzed Suzuki and Stille reactions is presented, without any indolic protective group. The central ring closure of the scaffold was performed through an electrophilic reaction on the position C-2 of the indole ring. The use of indole and 5-benzyloxyindole, along with substituted phenyl rings, generated three different scaffolds, which were successively exploited to modulate the structure. The cytotoxicity of the newly designed compounds on four cancer cell lines and activities against three kinases (CDK1, CDK5 and GSK3) were evaluated. Several compounds showed a marked cytotoxicity with IC(50) values in the sub-micromolar range, and induced important cell cycle perturbations, with a G2/M arrest. Some compounds revealed DNA binding properties and were found to inhibit topoisomerase-mediated DNA relaxation of supercoiled DNA, but these properties are not mandatory for a cytotoxic action. A novel lead compound () has been identified and warrants further investigations. 相似文献
78.
Ana Luiza Ribeiro de Souza Tatiana Andreani Fernando M. Nunes Douglas Lopes Cassimiro Adélia Emília de Almeida Clóvis Augusto Ribeiro Victor Hugo Vitorino Sarmento Maria Palmira Daflon Gremião Amélia M. Silva Eliana B. Souto 《Journal of Thermal Analysis and Calorimetry》2012,108(1):353-360
Praziquantel (PZQ) is the drug of choice for oral treatment of schistosomiasis and other fluke infections that affect humans. Its low oral bioavailability demands the development of innovative strategies to overcome the first pass metabolism. In this article, solid lipid nanoparticles loaded with PZQ (PZQ-SLN) were prepared by a modified oil-in-water microemulsion method selecting stearic acid as lipid phase after solubility screening studies. The mean particle size (Z-Ave) and zeta potential (ZP) were 500 nm and −34.0 mV, respectively. Morphology and shape of PZQ-SLN were analysed by scanning electron microscopy revealing the presence of spherical particles with smooth surface. Differential scanning calorimetry suggested that SLN comprised a less ordered arrangement of crystals and the drug was molecularly dispersed in the lipid matrix. No supercooled melts were detected. The entrapment efficiency (EE) and loading capacity of PZQ, determined by high performance liquid chromatography, were 99.06 ± 0.3 and 17.48 ± 0.05, respectively. Effective incorporation of PZQ into the particles was confirmed by small angle X-ray scattering revealing the presence of a lipid lamellar structure. Stability parameters of PZQ-SLN stored at room temperature (25 °C) and at 4 °C were checked by analysing Z-Ave, ZP and the EE for a period of 60 days. Results showed a relatively long-term physical stability after storage at 4 °C, without drug expulsion. 相似文献
79.
Whei Oh Lin José Américo de Azeredo Figueira Helmut G. Alt 《Monatshefte für Chemie / Chemical Monthly》1985,116(2):217-221
The syntheses of acyclic compounds featuring ether-amide groups and different terminal substituents are presented. Three series of new multidentate potential ligands were obtained.
Neue mehrzähnige potentielle Ionophore des Ether-Amid-Typs
Zusammenfassung Es wird die Synthese acyclischer Verbindungen mit Ether-Amid-Gruppen und verschiedenen endständigen Substituenten beschrieben. Es wurden drei Verbindungsreihen erhalten, die neue potentielle mehrzähnige Liganden repräsentieren.相似文献
80.
Santos MA Gil M Marques S Gano L Chaves S 《Analytical and bioanalytical chemistry》2005,381(2):413-419
A study of a series of bifunctional 3-hydroxy-4-pyridinone derivatives, containing side-chains with various alkyl-aryl-amine-amides as extra-functional groups, was conducted to assess the relevance of those groups to the Al-chelating affinity, the lipo–hydrophilic balance of the compounds, and 67Ga biodistribution in mice, in view of their potential use as Al-decorporating agents; the results were compared with those for the drug Deferriprone. Their acid–base properties and Al-chelating affinity in aqueous solution were studied by potentiometric techniques. These ligands form very stable tris-chelated Al complexes and the non-chelating extra-groups are only responsible for small differences in the complex stability (pAl1.2). At physiological pH the major ligand/complex species have different charges, because of the different extent of protonation of the ligands. The introduction of the different groups induces a well-balanced stepwise-like lipo–hydrophilic character (–0.2<log Doct./water<+1.1). The effect of each ligand on the biodistribution of 67Ga in overloaded mice is rapid blood clearance for all of them, but with different biodistribution patterns, namely excretion pathways and brain uptake/clearance, thus suggesting potential different clinical use. 相似文献