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1.
We investigate the conjecture that every circulant graph X admits a k‐isofactorization for every k dividing |E(X)|. We obtain partial results with an emphasis on small values of k. © 2006 Wiley Periodicals, Inc. J Combin Designs 14: 406–414, 2006 相似文献
2.
Danny E. Akin W. Herbert Morrison III Luanne L. Rigsby Franklin E. Barton II David S. Himmelsbach Kevin B. Hicks 《Applied biochemistry and biotechnology》2006,129(1-3):104-116
Information is presented on structure, composition, and response to enzymes of corn stover related to barriers for bioconversion
to ethanol. Aromatic compounds occurred in most tissue cell walls. Ferulic acid esterase treatment before cellulase treatment
significantly improved dry weight loss and release of phenolic acids and sugars in most fractions over cellulase alone. Leaf
fractions were considerably higher in dry weight loss and released sugars with esterase treatment, but stem pith cells gave
up the most phenolic acids. Results help identify plant fractions more appropriate for coproducts and bioconversion and those
more suitable as residues for soil erosion control. 相似文献
3.
G. Ferro-Flores F. De M. Ramírez M.G. Martínez-mendoza C. Arteaga de Murphy M. Pedraza-lópez L. García-salinas 《Journal of Radioanalytical and Nuclear Chemistry》2002,251(1):7-13
Lanreotide peptide was labeled with 153Sm-H1ETA and 188Re-MAG3 in order to evaluate whether or not their conjugation to the peptide produce significant differences of the in vitro lipophilicity with respect to the 188Re-lanreotide prepared by the direct labeling method (highly lipophilic). The differences of lipophilicity between the complexes, were evaluated using a reverse phase HPLC system. The measured lipophilicity of 153Sm-H1ETA-lanreotide, 188Re-MAG3-lanreotide and 188Re-lanreotide was taken to be the capacity factor [k" = (t
R-t
0)/t
0 where t
R is the retention time and t
0 is the dead time] for each of the complexes under identical chromatography conditions. Results showed that the in vitro lipophilicity decreased in the order 188Re-lanreotide (direct labeling), 188Re-MAG3-lanreotide and 153Sm-H1ETA-lanreotide. Since the last one has a capacity factor (k") similar to that of 188Re-MAG3, some renal elimination for 153Sm-H1ETA-lanreotide could be expected, which probably would reduce the unnecessary radiation dose to normal tissues. 相似文献
4.
J. Howard Rytting Danny R. McHan Takeru Higuchi David J. W. Grant 《Journal of solution chemistry》1986,15(8):693-703
Henry's law constants have been determined for -butyrolactone (BL), ethyl acetate (EA), and 2-methyl-3-pentanol (MEP) in mixtures of iso-octane (ISO) and toluene (TOL), for BL, EA, TOL, and ISO in cinnamaldehyde (CIN) and for TOL and ISO in each other and in BL. From these data and published vapor pressures, the activity coefficients at infinite dilution and the standard molar Gibbs free energy of transfer, G
2
0
of the solutes from dilute solution in ISO to dilute solution in each solvent medium have been calculated. The different behavior patterns of BL and EA are attributed to differences in their abilities to exist in different conformations possessing different dipole moments. For polar solutes, G
2
0
decreases with increasing polarizability of the solvent and with increasing dipole moment of the solute, suggesting increased contributions from dipole-induced dipole (Debye) interactions. The sigmoidal plot of G
2
0
against the change in pair potential energy calculated from the classical expressions suggests that G
2
0
seriously underestimates the strength of the Debye interactions in comparison with the London interactions. 相似文献
5.
Wen-Ping Wang Robert G. Parr Danny R. Murphy George A. Henderson 《Chemical physics letters》1976,43(3):409-412
It is demonstrated that the ground-state atomic kinetic energy functional T[?], where ? is the electron density, can be computed to surprising accuracy from the truncated gradient expansion: T[?] = + T2[?] + T4[?], with To[?] = (3π2) ∫ ? dτ, T2 [?] = ∫ (??)2??1 dτ, and T4 [?] given by the formula of Hodges. Calculations of T0, T2 and T4 are reported for He with ? both the Hartree—Fock and a very accurate density, and for Ne, Ar and Kr with ? the Hartree—Fock density. For Kr, T0 + T2 + T4 is within 0.3% of the exact Hartree—Fock T, with T2/T0 = 0.05, T4/T2 = 0.17. 相似文献
6.
The asymmetric total synthesis of (-)-reveromycin A is described. The key steps involved a Lewis acid catalyzed inverse electron demand hetero-Diels-Alder reaction followed by hydroboration/oxidation to afford the spiroketal core 4 in a highly stereoselective manner and introduction of the C18 hemisuccinate by high-pressure acylation. 相似文献
7.
A new branched-pore adsorption model has been developed using an external mass transfer coefficient, K
f, an effective diffusivity, D
eff, a lumped micropore diffusion rate parameter, K
b, and the fraction of macropores, f, to describe sorption kinetic data from initial adsorbent-adsorbate contact to the long-term adsorption phase. This model has been applied to an environmental pollution problem—the removal of two dyes, Acid Blue 80 (AB80) and Acid Red 114 (AR114), by sorption on activated carbon. A computer program has been used to generate theoretical concentration-time curves and the four mass transfer kinetic parameters adjusted so that the model achieves a close fit to the experimental data. The best fit values of the parameters have been determined for different initial dye concentrations and carbon masses. Since the model is specifically applicable to fixed constant values of these four parameters, a further and key application of this project is to see if single constant values of these parameters can be used to describe all the experimental concentration-time decay curves for one dye-carbon system.The error analysis and best fit approach to modeling the decay curves for both dye systems show that the correlation between experimental and theoretical data is good for the fixed values of the four fitted parameters. A significantly better fit of the model predictions is obtained when K
f, K
b and f are maintained constant but D
eff is varied. This indicates that the surface diffusivity may vary as a function of surface coverage. 相似文献
8.
A.G. Gonzalez J.M. Arteaga J.J. Fernandez J.D. Martin M. Norte J.Z. Ruano 《Tetrahedron》1984,40(14):2751-2755
The structures of three brominated terpenoids which are natural products from the red alga Laurencia pinnatifida (Gmal. Lamour) are described. The structures of the sesquiterpenes and were determined by spectral comparison and chemical interconversion. The structure of the squalene-derived terpenoid was secured by chemical transformation into thyrsiferol, a brominated triterpene previously isolated from the red alga Laurencia thyrsifera. 相似文献
9.
E. M. Molina-Trinidad C. Arteaga de Murphy H. Jung-Cook 《Journal of Radioanalytical and Nuclear Chemistry》2004,260(3):477-489
Good manufacturing practices specify that a well-type scintillation NaI(Tl) crystal detector has to be validated in order
to detect radioactivity from any radiopharmaceutical used to obtain radiopharmacokinetic parameters. A 5 cm well-type NaI(Tl)
scintillation detector was coupled to a multi-channel analyzer centered at the 140 keV 99mTc peak with a 20% window. The area represents counts per minute (cpm). All the net cpm were decay corrected. The activity
source was 99mTc-glucarate developed as an imaging agent for acute myocardial infarction. Wistar rats were injected in a tail vein with
0.1 ml (3.7 MBq) of 99mTc-glucarate solution and 13 blood samples were taken. The cpm were the input data for the WINNONLN program which calculates
radiopharmacokinetic parameters. The detector's efficiency for 99mTc was 15.03% and the sensitivity 1.12 kBq/ml in plasma. The response was linear between 0.31-14.3 kBq/ml of 99mTc-glucarate. The maximum assay variation coefficient was 2.79 and recovery of 99mTc-glucarate in plasma was 99.8%±0.2%. LOD was 0.31 kBq and LOQ = 1.12 kBq in plasma samples. 99mTc-glucarate follows a two-compartment model of distribution with Vd of 21.74 ml±2.71 ml; a Vdss of 74.36 ml±12.67 ml; t
1/2
a0.74 h±0.19 h; t
1/2
b 18.98 h±4.36 h; AUC = 32.75 mCi/min.ml ± 3.73 mCi/min.ml; MRT = 24.35 h±5.51 h and total clearance 3.05 ml/h±0.35 ml/h. The well-type detector fulfills the quality system requirements
and the radiopharmacokinetic parameters for 99mTc-glucarate in rats are reliable.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
10.
The synthesis of the green cyclopentadiene-fused dimethyldihydropyrene 12 was achieved in 36% yield in 7 steps from the parent dihydropyrene 3. Reaction of 12 with KH or LiCH(2)SiMe(3) gave the [14]annulene-fused cyclopentadienide anion quantitatively. In the (1)H NMR spectra, the internal methyl protons of 12 at delta -3.9, change dramatically on formation of anion 5, becoming deshielded to delta -1.82. This is caused by the reduction in diatropicity of the [14]annulene ring on fusion to the 6pi-cyclopentadienide ring. The anion is also a photochromic switch. Irradiation of the closed form 5 with visible light opens it to the open form 5', which reverts to the closed form 5 either with UV light or thermally. The switching behavior is between that of the parent 3/3' and the benzannelated system 4/4' and suggests that in its effect on the photoswitching, cyclopentadienide is behaving chemically similar to benzene. 相似文献