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71.
This paper deals with a chance constrained programming model, where both fuzziness and randomness are present in the objective
function and constraints. The concept of fuzzy random variable, mean and variance of fuzzy random variable, minimum of fuzzy
numbers are used in the model. The methodology is verified through a numerical example. 相似文献
72.
The naturally occurring phytotoxic noneolide stagonolide-C has been synthesized by a chemo-enzymatic approach. Two key intermediates have been synthesized by applying a metal–enzyme combined DKR (dynamic kinetic resolution) strategy, followed by RCM (ring-closing metathesis) to afford the target compound in an efficient way. 相似文献
73.
Prabu Manoharan R. S. K. Vijayan Nanda Ghoshal 《Journal of computer-aided molecular design》2010,24(10):843-864
The ability to identify fragments that interact with a biological target is a key step in FBDD. To date, the concept of fragment
based drug design (FBDD) is increasingly driven by bio-physical methods. To expand the boundaries of QSAR paradigm, and to
rationalize FBDD using In silico approach, we propose a fragment based QSAR methodology referred here in as FB-QSAR. The FB-QSAR methodology was validated
on a dataset consisting of 52 Hydroxy ethylamine (HEA) inhibitors, disclosed by GlaxoSmithKline Pharmaceuticals as potential anti-Alzheimer agents. To address the issue of target selectivity, a major confounding factor
in the development of selective BACE1 inhibitors, FB-QSSR models were developed using the reported off target activity values.
A heat map constructed, based on the activity and selectivity profile of the individual R-group fragments, and was in turn
used to identify superior R-group fragments. Further, simultaneous optimization of multiple properties, an issue encountered
in real-world drug discovery scenario, and often overlooked in QSAR approaches, was addressed using a Multi Objective (MO-QSPR)
method that balances properties, based on the defined objectives. MO-QSPR was implemented using Derringer and Suich desirability
algorithm to identify the optimal level of independent variables (X) that could confer a trade-off between selectivity and activity. The results obtained from FB-QSAR were further substantiated
using MIF (Molecular Interaction Fields) studies. To exemplify the potentials of FB-QSAR and MO-QSPR in a pragmatic fashion,
the insights gleaned from the MO-QSPR study was reverse engineered using Inverse-QSAR in a combinatorial fashion to enumerate
some prospective novel, potent and selective BACE1 inhibitors. 相似文献
74.
In methanol, the reaction of Cu(ClO(4))(2).6H(2)O and a sterically constrained piperazine imine phenol ligand (H(2)L), in the presence of NEt(3), affords a novel tetranuclear copper(II) complex of formula [Cu(II)(4)(mu(3)-L)(2)(mu-OH)(2)(H(2)O)(2)](ClO(4))(2).H(2)O (1). The X-ray structure of this complex shows an elongated Cu(4) quasi-tetrahedron coordinated to two hexadentate chair-(e,a)-mu(3)-piperazine bridging ligands. Variable-temperature magnetic studies show an S(t) = 0 spin ground state resulting from antiferromagnetic interactions between Cu(II) ions within the complex. 相似文献
75.
The current study addresses the mathematical modeling aspects of transport phenomena in steady, two-dimensional, laminar flow accompanied by heat transfer in a lid-driven differentially heated cavity in presence of radiatively absorbing, emitting and scattering gray medium. The walls of the enclosure are considered to be opaque, diffusive and gray. Mixed convection is the outcome of the interaction of forced convection induced by the moving vertical hot and cold wall with the natural convection induced due to the differentially heated enclosure. Two different orientations of the wall movement have been considered to simulate opposing and aiding mixed convection phenomenon and to study its interaction with radiation. Vorticity-stream function formulation of N–S equation has been employed. The discrete ordinate method has been used in modeling the radiative transport equation followed with finite volume method as discretisation technique. The effect of influencing parameters on fluid flow and heat transfer has been studied. 相似文献
76.
Aniol KA Armstrong DS Averett T Benaoum H Bertin PY Burtin E Cahoon J Cates GD Chang CC Chao YC Chen JP Choi S Chudakov E Craver B Cusanno F Decowski P Deepa D Ferdi C Feuerbach RJ Finn JM Frullani S Fuoti K Garibaldi F Gilman R Glamazdin A Gorbenko V Grames JM Hansknecht J Higinbotham DW Holmes R Holmstrom T Humensky TB Ibrahim H de Jager CW Jiang X Kaufman LJ Kelleher A Kolarkar A Kowalski S Kumar KS Lambert D LaViolette P LeRose J Lhuillier D Liyanage N Margaziotis DJ Mazouz M McCormick K 《Physical review letters》2006,96(2):022003
We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from 4He at an average scattering angle = 5.7 degrees and a four-momentum transfer Q2 = 0.091 GeV2 . From these data, for the first time, the strange electric form factor of the nucleon G(E)s can be isolated. The measured asymmetry of A(PV) = (6.72 +/- 0.84(stat) +/- 0.21(syst) x 10(-6) yields a value of G(E)s = -0.038 +/- 0.042(stat) +/- 0.010(syst), consistent with zero. 相似文献
77.
78.
Four isomeric hydroxy-skipped bishomo-inositol analogs have been synthesized from both enantiomers of 5-hydroxymethyl-2-cyclohexenone. Sharpless asymmetric dihydroxylation and substrate-directed anionic hydroxymethylation are the key reactions which have been employed successfully for the synthesis of new cyclitols. The synthesized cyclitols have been screened for their inhibitory effect on α- and β-glycosidases. 相似文献
79.
Nancy Ghosh S Singh N Kaur Nanda G Venugopalan P Bharatam PV Trehan S 《Chemical communications (Cambridge, England)》2003,(12):1420-1421
The origin of diastereoselectivity in the addition of alkyl lithium to chiral Schiff bases has been investigated experimentally and theoretically and the formation of the major diastereomer can be explained from the energy minimized structure of the Schiff base in which the phenyl group has been found to orient in such a manner that it posed lesser steric hindrance to the incoming nucleophile as compared to the alkyl group. 相似文献
80.
We describe a method for predicting detection limits of minority elements in electron energy loss spectroscopy (EELS), and its implementation as a software package that gives quantitative predictions for user-specified materials and experimental conditions. The method is based on modeling entire energy loss spectra, including shot noise as well as instrumental noise, and taking into account all the relevant experimental parameters. We describe the steps involved in modeling the entire spectrum, from the zero loss up to inner shell edges, and pay particular attention to the contributions to the pre-edge background. The predicted spectra are used to evaluate the signal-to-noise ratios (SNRs) for inner shell edges from user-specified minority elements. The software also predicts the minimum detectable mass (MDM) and minimum mass fraction (MMF). It can be used to ascertain whether an element present at a particular concentration should be detectable for given experimental conditions, and also to quickly and quantitatively explore ways of optimizing the experimental conditions for a particular EELS analytical task. We demonstrate the usefulness of the software by confirming the recent empirical observation of single atom detection using EELS of phosphorus in thin carbon films, and show the effect on the SNR of varying the acquisition parameters. The case of delta-doped semiconductors is also considered as an important example from materials science where low detection limits and high spatial resolution are essential, and the feasibility of such characterization using EELS is assessed. 相似文献