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971.
The frequency-dependent polarizabilities of closed-shell sodium clusters containing up to 20 atoms have been calculated using the linear complex polarization propagator approach in conjunction with Hartree-Fock and Kohn-Sham density functional theories. In combination with polarizabilities for C(60) from a previous work [J. Chem. Phys. 123, 124312 (2005)], the C(6) dipole-dipole dispersion coefficients for the metal-cluster-to-cluster and cluster-to-buckminster-fullerene interactions are obtained via the Casimir-Polder relation [Phys. Rev. 73, 360 (1948)]. The B3PW91 results for the polarizability of the sodium dimer and tetramer are benchmarked against coupled cluster calculations. The error bars of the reported theoretical results for the C(6) coefficients are estimated to be 5%, and the results are well within the error bars of the experiment. 相似文献
972.
Varnum SM Warner MG Dockendorff B Anheier NC Lou J Marks JD Smith LA Feldhaus MJ Grate JW Bruckner-Lea CJ 《Analytica chimica acta》2006,570(2):137-143
Two immunoassay platforms were developed for either the sensitive or rapid detection of botulinum neurotoxin A (BoNT/A), using high-affinity recombinant monoclonal antibodies against the receptor binding domain of the heavy chain of BoNT/A. These antibodies also bind the same epitopes of the receptor binding domain present on a nontoxic recombinant heavy chain fragment used for assay development and testing in the current study. An enzyme-linked immunosorbent assay (ELISA) microarray using tyramide amplification for localized labeling was developed for the specific and sensitive detection of BoNT. This assay has the sensitivity to detect BoNT in buffer and blood plasma samples down to 14 fM (1.4 pg mL−1). Three capture antibodies and one antibody combination were compared in the development of this assay. Using a selected pair from the same set of recombinant monoclonal antibodies, a renewable surface microcolumn sensor was developed for the rapid detection of BoNT/A in an automated fluidic system. The ELISA microarray assay, because of its sensitivity, offers a screening test with detection limits comparable to the mouse bioassay, with results available in hours instead of days. The renewable surface assay is less sensitive but much faster, providing results in less than 10 min. 相似文献
973.
Adams CJ Baber RA Batsanov AS Bramham G Charmant JP Haddow MF Howard JA Lam WH Lin Z Marder TB Norman NC Orpen AG 《Dalton transactions (Cambridge, England : 2003)》2006,(11):1370-1373
The reaction between [Co(PMe3)4] and B2(4-Mecat)2 (4-Mecat = 1,2-O2-4-MeC6H3) or between [Co(PMe2Ph)4] and B2(cat)2 (cat = 1,2-O2C6H4) affords the paramagnetic Co(II) bisboryl complexes [Co(PMe3)3[B(4-Mecat)]2] and [Co(PMe2Ph)3{B(cat)]2] respectively, both of which have been structurally characterised. ESR data and preliminary diboration and boryl transfer reactivity studies are also presented. The reaction between [CoMe(PMe3)4] and B2(cat)2 affords the Co(I) monoboryl complex [Co(PMe3)4[B(cat)]]. 相似文献
974.
The manufacture of micro-HPLC columns with combined stationary phases, a body of 3.5-μm XTerra-C18 particles, and poly(styrene–divinylbenzene) (PS–DVB) frits is described in detail. The efficiency of the columns was assessed by rapid separation of neutral and acid compound mixtures. Direct analysis of some pharmaceuticals in plasma resulted in lower limits of detection (LOD) for salmeterol xinofate of 12.5 nanograms on-column. 相似文献
975.
Bazhirov T. T. Norman G. E. Stegailov V. V. 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2006,80(1):S90-S97
The molecular dynamics method was used to simulate cavitation in a metastable lead melt and determine the stability limits. States at temperatures below critical (T < 0.5T c) and large negative pressures were considered. Interatomic interactions were described by the realistic embedded atom potential. The kinetic boundary of liquid phase stability was shown to be different from the spinodal. The kinetics and dynamics of cavitation were studied. The pressure dependences of cavitation frequencies were obtained over the temperature range 700–2700 K. The results of molecular dynamics calculations were compared with estimates based on classical nucleation theory. 相似文献
976.
Norman J. Morgenstern Horing 《Physics letters. A》2010,374(34):3551-3553
We analyze the energy spectrum and propagation of electrons in a quantum wire on a 2D host medium in a normal magnetic field, representing the wire by a 1D Dirac delta function potential which would support just a single subband state in the absence of the magnetic field. The associated Schrödinger Green's function for the quantum wire is derived in closed form in terms of known functions and the Landau quantized subband energy spectrum is examined. 相似文献
977.
Norman C. Craig Matthew C. Leyden Amie K. Patchen Thomas A. Blake Robert L. Sams 《Journal of Molecular Spectroscopy》2010,262(1):49-60
Assignments of the vibrational fundamentals of cis- and trans-1,3,5-hexatriene are reevaluated with new infrared and Raman spectra and with quantum chemical predictions of intensities and anharmonic frequencies. The rotational structure is analyzed in the high-resolution (0.0013-0.0018 cm−1) infrared spectra of three C-type bands of the trans isomer and two C-type bands of the cis isomer. The bands for the trans isomer are at 1010.96 cm−1 (ν14), 900.908 cm−1 (ν16), and 683.46 cm−1 (ν17). Ground state (GS) rotational constants have been fitted to the combined ground state combination differences (GSCDs) for the three bands of the trans isomer. The bands for the cis isomer are at 907.70 cm−1 (ν33) and 587.89 cm−1 (ν35). GS rotational constants have been fitted to the combined GSCDs for the two bands of the cis isomer and compared with those obtained from microwave spectroscopy. Small inertial defects in the GSs confirm that both molecules are planar. Upper state rotational constants were fitted for all five bands. 相似文献
978.
Norman MR Kaminski A Rosenkranz S Campuzano JC 《Physical review letters》2010,105(18):189701; author reply 189702
979.
Poly-hexafluoropropylene oxide (poly-HFPO) alcohol was prepared by the reduction of the corresponding methyl ester using NaBH4, NaBD4, or LiAlH4 (LAH). This alcohol is a versatile starting material for the preparation of additional interesting compounds. Because of its expected poor nucleophilicity, before attempting additional reactions, we have found it advantageous to prepare a corresponding salt. We have found that the resulting salt behaved like a normal hydrocarbon alkoxide. The reaction of this salt with either acetyl chloride or allyl chloride (or bromide) gave the expected products which proved to be normal nucleophilic substitutions. In addition, the bromination of the allyl ether was studied using NMR and GC/MS techniques. 相似文献
980.