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61.
Kamil Hoffmann Joanna Wiśniewska Anna Kaczmarek-Kędziera Joanna Wietrzyk 《Journal of Coordination Chemistry》2015,68(17-18):3193-3208
The reaction of silver acetate with cis-[PtI2(dbtp)2], where dbtp = 5,7-ditertbutyl-1,2,4-triazolo-[1,5-a]pyrimidine, yielded cis-[Pt(OOCCH3)2(dbtp)2]·dmf (1). The complex has been analyzed by multinuclear magnetic resonance (1H, 13C, 15N), IR, and Raman. The compound formed two rotamers in CDCl3 and its spatial structures have been optimized using computational calculation. It was found that head-to-tail rotamer (1a) is more stable than its head-to-head counterpart (1b). In vitro antiproliferative activity against four tumor cell lines (A549, T47D, FaDu, and A2780cis) revealed in all cases significant cytotoxicity (IC50 = 0.26–1.80 μM), possessing IC50 values at least fivefold lower than cisplatin, carboplatin, and oxaliplatin (except A2780cis). The remarkable in vitro activity against T47D and A2780cis suggested the ability to overcome cisplatin resistance in these types of tumor cells. In addition, in vitro toxicity was evaluated against BALB/3T3 and has shown that the lipophilic platinum(II) complex (1) inhibits cell proliferation weaker than cisplatin and oxaliplatin. Additionally, cis-[Pt(OOCCH3)2(dbtp)2]·dmf exhibited selective activity, in contrast to cisplatin or oxaliplatin. 相似文献
62.
It has been shown by Pindera and Mazurkiewicz that a new type of scattered-light modulation in the plane of a two-dimensional photoelastic object can be obtained when the stationary integrated photoelastic method developed by Pindera and Straka is applied in a scanning mode and when the transfer function of the photoelastic system satisfies certain conditions. The new type of light modulation, called field of isodynes by the authors, carries information on stress components normal to the direction of propagation of primary beam, and on corresponding total-force component. The points where this stress component is equal to zero can be easily determined. The classical scattered-light modulation along a chosen line represents a cross section of a corresponding isodynes field. It is shown that these features of the method of isodynes make it possible to easily determine the distribution and values of normal stress components at any arbitrary rectilinear cross section, and to check immediately the accuracy of measurements. The experimental determination of contact stresses and contact regions using the method of isodynes is especially simple and elegant. 相似文献
63.
Kamil I. Utegenov 《Journal of organometallic chemistry》2011,696(21):3408-3414
The addition of phosphines to the manganese allenylidene complexes Cp(CO)2MnCCC(Ph)R (R = H, Ph) proceeds selectively at the Cα atom to result in the α-phosphonioallenyl complexes Cp(CO)2Mn−-C(+PR31)CC(Ph)R. The protonation of the latter affords the η2-(1,2)-phosphonioallenes Cp(CO)2Mn{η2-(1,2)-HC(+PR31)CC(Ph)R}, rather than the phosphoniovinylcarbenes Cp(CO)2MnC(+PR31)-HCC(Ph)R. All complexes obtained are stereochemically rigid and do not isomerize into the η2-(2,3)-phosphonioallene isomers. 相似文献
64.
Urszula Domańska Kamil Paduszyński Zuzanna Żołek-Tryznowska 《The Journal of chemical thermodynamics》2011,43(2):167-171
(Liquid + liquid) phase equilibria (LLE) of binary mixtures containing hyperbranched polymer Boltorn® H2004 and n-alkanes (n-hexane, n-heptane, n-octane, and n-decane) were studied over the temperature range from about (260 up to 360) K. The polymer is partially miscible with n-alkanes and the solubility decreases with an increase of the chain length of the solvent. Corresponding LLE phase diagrams including spinodal and binodal (liquid + liquid) coexistence curves were calculated in terms of the statistical mechanics – based on the lattice-cluster theory, based only on the upper critical solution temperature, and the polymer chain architecture. The results show semi-qualitative agreement of predicted and experimental equilibrium compositions and temperatures. Boltorn® H2004 reveals complete miscibility in the liquid phase with alcohols (C1–C8), aromatic hydrocarbons (benzene, toluene, and thiophene), and ethers (methyl tetra-butyl ether, ethyl tetra-butyl ether, and tetrahydrofurane). 相似文献
65.
66.
Olive AG Parkan K Givelet C Michl J 《Journal of the American Chemical Society》2011,133(50):20108-20111
Supramolecular self-assembly using weak interactions under quasi-equilibrium conditions has provided easy access to very complex but often quite fragile molecules. We now show how a labile structure obtained from reversible transition-metal-directed self-assembly of rods and connectors serves as a template that can be converted into a sturdy structure of identical topology and similar geometry. The process consists of Cu(I)-catalyzed replacement of all rods or connectors terminated with pyridines for analogues terminated with ethynyls, converting dative N→Pt(+) bonds into covalent C-Pt bonds. The procedure combines the facility and high yield of reversible self-assembly with the robustness of covalent synthesis. 相似文献
67.
Mohd. Imran Ansari Ravi Shankar Mohd. Kamil Hussain Ruchir Kant Prakash R. Maulik K. Ravi Kumar K. Hajela 《Journal of heterocyclic chemistry》2011,48(6):1336-1341
Mono‐ and bis‐diaryl‐2H‐1,4‐benzothiazines were obtained in quantitative yields through silica‐supported perchloric acid catalyzed reaction cascade of double condensation and 1,4 addition of diaroylacetylenes with 2‐aminothiophenol at room temperature. The structures were confirmed by spectroscopic analyses and X‐ray crystallographic studies. J. Heterocyclic Chem., (2011) 相似文献
68.
69.
Szyperska A Gajewicz A Mazurkiewicz K Leszczynski J Rak J 《Physical chemistry chemical physics : PCCP》2011,13(43):19499-19507
Electron attachment to trimeric complexes that mimic most frequent hydrogen bonding interactions between an amino acid side chain (AASC) and the Watson-Crick (WC) 9-methyladenine-1-methylthymine (MAMT) base pair has been studied at the B3LYP/6-31++G(d,p) level of theory. Although the neutral trimers will not occur in the gas phase due to unfavorable free energy of stabilization (G(stab)) they should form a protein-DNA complex where entropy changes related to formation of such a complex will more than balance its disadvantageous G(stab). The most stable neutrals possess an identical pattern of hydrogen bonds (HBs). In addition, the proton-acceptor (N7) and proton-donor (N10) atoms of adenine involved in those HBs are located in the main groove of DNA. All neutral structures support the adiabatically stable valence anions in which the excess electron is localized on a π* orbital of thymine. The vertical detachment energies (VDEs) of anions corresponding to the most stable neutrals are substantially smaller than that of the isolated WC MAMT base pair. Hence, electron transfer from the anionic thymine to the phosphate group and as a consequence formation of a single strand break (SSB) should proceed more efficiently in a protein-dsDNA complex than in the naked dsDNA as far as electron attachment to thymine is concerned. 相似文献
70.
Sevda Yldz Fadime Dirik Kamil Demirci 《Mathematical Methods in the Applied Sciences》2019,42(16):5371-5382
In this paper, we study the Korovkin type approximation theorem for Ka‐ convergence, which is an interesting convergence method on weighted spaces. We also study the rate of Ka?convergence by using the weighted modulus of continuity and afterwards, we present a nontrivial application. 相似文献