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1.
Lorraine R. Gardiner Ralph E. Steuer 《The Journal of the Operational Research Society》1994,45(12):1456-1466
It has previously been shown that nine of the most prominent procedures of interactive multiple objective programming can be considered as special cases of a common procedure called the unified algorithm. In this paper, we show how four additional procedures can be similarly included in the unified approach. Also, the paper presents a procedure-switching matrix that depicts the possibilities for switching from one procedure to another, one iteration to the next, in the unified algorithm if so directed by a user. 相似文献
2.
Mishra SR Bachmann KT Bernstein RH Blair RE Foudas C Lefmann WC Leung WC Oltman E Quintas PZ Sciulli FJ Shaevitz MH Smith WH Merritt FS Oreglia MJ Schellman H Schumm BA Borcherding F Fisk HE Lamm MJ Marsh W Merritt KW Yovanovitch DD Bodek A Budd HS Sakumoto WK 《Physical review letters》1989,63(2):132-135
3.
Abstract— Comparison of spectroradiometric and meter measurements of a series of ultraviolet radiation sources indicates that a wide divergence between readings can occur. We found that with a xenon are filtered as a solar simulator producing UV-A (320–400 nm) and UV-B (290–320 nm) radiation, the meter can either over-or underestimate the emission of the source when different cutoff filters are used. The most severe discrepancy appears with the UV-B meter reading, although the UV-A reading can also be problematic. Meters should be calibrated against the specific sources they will be used to measure. 相似文献
4.
Kevin J. Sheehy Lorraine M. Bateman Niko T. Flosbach Martin Breugst Peter A. Byrne 《Chemical science》2020,11(35):9630
The preferred site of alkylation of diazine N-oxides by representative hard and soft alkylating agents was established conclusively using the 1H–15N HMBC NMR technique in combination with other NMR spectroscopic methods. Alkylation of pyrazine N-oxides (1 and 2) occurs preferentially on nitrogen regardless of the alkylating agent employed, while O-methylation of pyrimidine N-oxide (3) is favoured in its reaction with MeOTf. As these outcomes cannot be explained in the context of the hard/soft acid/base (HSAB) principle, we have instead turned to Marcus theory to rationalise these results. Marcus intrinsic barriers (ΔG‡0) and ΔrG° values were calculated at the DLPNO-CCSD(T)/def2-TZVPPD/SMD//M06-2X-D3/6-311+G(d,p)/SMD level of theory for methylation reactions of 1 and 3 by MeI and MeOTf, and used to derive Gibbs energies of activation (ΔG‡) for the processes of N- and O-methylation, respectively. These values, as well as those derived directly from the DFT calculations, closely reproduce the observed experimental N- vs. O-alkylation selectivities for methylation reactions of 1 and 3, indicating that Marcus theory can be used in a semi-quantitative manner to understand how the activation barriers for these reactions are constructed. It was found that N-alkylation of 1 is favoured due to the dominant contribution of ΔrG° to the activation barrier in this case, while O-alkylation of 3 is favoured due to the dominant contribution of the intrinsic barrier (ΔG‡0) for this process. These results are of profound significance in understanding the outcomes of reactions of ambident reactants in general.Marcus theory enables rationalisation and quantification of selectivities in reactions of ambident nucleophiles for which the HSAB principle cannot operate. 相似文献
5.
Arroyo CG King BJ Bachmann KT Bazarko AO Bolton T Foudas C Lefmann WC Leung WC Mishra SR Oltman E Quintas PZ Rabinowitz SA Sciulli FJ Seligman WG Shaevitz MH Merritt FS Oreglia MJ Schumm BA Bernstein RH Borcherding F Fisk HE Lamm MJ Marsh W Merritt KW Schellman HM Yovanovitch DD Bodek A Budd HS de Barbaro P Sakumoto WK Kinnel T Sandler PH Smith WH 《Physical review letters》1994,72(22):3452-3455
6.
Lorraine P. McDonnell Bushnell Eric R. Evitt Robert G. Bergman 《Journal of organometallic chemistry》1978,157(4):445-456
Reactions of η5-cyclopentadienylbis(triphenylphosphine)cobalt(I) (5) with several 2,n-alkadiynes (2) were investigated. Each of these reactions leads initially to a material in which one of the acetylene functional groups is π-coordinated to cobalt; this complex then undergoes conversion to a metallocycle. In cases where the two acetylene functions are connected by three- and four-carbon bridges (2b, 2c), metallocycles formed by intramolecular reaction of two acetylene functions in the same molecule may be isolated. In cases where the acetylene functions are joined by larger or smaller bridges, the reactions are more complex, and both inter- and intramolecular metallocycles are formed. Reactions of 5 with 1,8-bis(trimethylsilyl)-1,7-octadiyne (16) gives an isolable crystalline mono-acetylene complex (17), this material is stable in the solid state but undergoes conversion to metallocycle (18) in benzene solution. The relationship of these results to the mechanism of the CpCo(CO)2-catalyzed benzocycloalkene synthesis is discussed; it is suggested that intramolecular metallocycles are intermediates in reactions leading to benzocyclopentanes and -cyclohexenes, but intermolecular metallocycles are probably involved in reactions leading to benzocyclobutenes. 相似文献
7.
Pyrazines and quinoxalines bearing 2-substituents that direct ortho metalation reacted with lithium 2,2,6,6-tetramethylpiperidide to produce 2-substituted-3-lithiopyrazines and quinoxalines. These lithio reagents reacted with N-methoxy-N-methylbenzamide to give good to moderate yields of 3-substituted pyrazinyl or quinoxalinylphenylmethanones. The 3-methylthio substituents of some ketone products were oxidized to methylsulfonyl groups that were susceptible to nucleophilic displacement. 相似文献
8.
Charles Merritt Gary W. Scott Amitava Gupta Andre Yavrouian 《Chemical physics letters》1980,69(1):169-173
Transient absorption spectra (400–600 nm) of 2-hydroxybenzophenone and the methyl methacrylate copolymer of 2-hydroxy, 3-allyl, 4,4'-dimethoxybenzophenone following 355 nm excitation (7–480 ps delay) are reported. A short-lived, 435 nm transient (τ ≈ 10 ps in CH2Cl2) for both molecules is assigned to the lowest excited singlet before internal proton transfer. Weaker, broad T-T absorption is observed after 480 ps. 相似文献
9.
Gérald Perron Lorraine Couture Jacques E. Desnoyers 《Journal of solution chemistry》1992,21(5):433-443
Liquid systems which have strong non-idealities, as seen from their thermodynamic properties, often show evidence of these interactions in the solid-liquid phase diagrams. This suggests that some of the structures present in the solid state can persist in the solution state, on a time average, up to temperatures much higher than the melting point. Volumes and heat capacities of typical systems were either taken from the literature or measured to illustrate this correlation with the phase diagrams. With mixtures of aprotic solvents which show nearly-ideal simple eutectic phase diagrams, the properties of the solutions are also nearly ideal. Examples of systems investigated which show strong non-idealities are ionic surfactant solutions, alcohol-water mixtures, chloroform-triethylamine mixtures and lithium salts in aprotic solvents.Paper written in the honor of Loren Hepler on the occasion of his retirement. 相似文献
10.
Lynch CL Hale JJ Budhu RJ Gentry AL Finke PE Caldwell CG Mills SG MacCoss M Shen DM Chapman KT Malkowitz L Springer MS Gould SL DeMartino JA Siciliano SJ Cascieri MA Carella A Carver G Holmes K Schleif WA Danzeisen R Hazuda D Kessler J Lineberger J Miller M Emini E 《Organic letters》2003,5(14):2473-2475
[reaction: see text] A novel approach to alpha,alpha-disubstituted-beta-amino acids (beta(2,2)-amino acids) was employed in the synthesis of a series of 3-(pyrrolidin-1-yl)propionic acids possessing high affinity for the CCR5 receptor and potent anti-HIV activity. The rat pharmacokinetics for these new analogues featured higher bioavailabilities and lower rates of clearance as compared to cyclopentane 1. 相似文献