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101.
Maass JS Zeller M Breault TM Bartlett BM Sakiyama H Luck RL 《Inorganic chemistry》2012,51(9):4903-4905
The syntheses and structural properties of three dinuclear complexes [L(3)Co(μ(2)-O(2)P(Bn)(2))(3)CoL'][L"] [one ionic L(3) = py(3), L' = py, L" = ClO(4)(-) (1) and two molecular L(3) = py(3), L' = Cl (2) and L(3) = py, μ(2)-NO(3)(-), L' = py (3)] are reported. Complexes feature octahedral Co(II) sites bridged by three dibenzylphosphinate ligands to a tetrahedrally ligated Co(II) site, with the remaining coordination sites occupied by py, nitrato, and Cl ligands. The Co-Co distances are 4.248 ? at 291 K and 4.265 ? at 100 K for 1 and 4.278 and 4.0313(7) ? for 2 and 3, respectively at 100 K. A fit of the low-temperature magnetic susceptibility data was derived for complex 1 with g = 2.25, TIP = 700 × 10(-6) cm(3) mol (-1), λ = -173 cm(-1), κ = 0.93, ν = -3.9, Δ = 630 cm(-1), J = 0.15 cm(-1), and θ = -1.8 resulting in R(χ(M)) = 2.5 × 10(-5) and R(χ(M)T) = 5.8 × 10(-5). 相似文献
102.
Abstract
Hydroxymethylphenylphosphinic acid, 1 was synthesized and structurally characterized by single crystal X-ray diffraction. Ligand 1 crystallized in the monoclinic P21 space group with two molecules comprising the unit cell and cell dimensions a = 7.5587(13) ?, b = 5.9019(8) ?, c = 8.808(3) ? and β = 90.90(2)°. Molecules were linked up by hydrogen bonding involving all three oxygen atoms of 1 resulting in 2-dimensional sheets. Reacting 1 with MoO2Cl2 in a mixture of ethanol and dichloromethane afforded the dinuclear molybdenum complex Mo2O4Cl2[(HOCH2)PhPOO]2, 2 where the two molybdenum atoms were bridged by the phosphinate ligand. Complex 2 crystallized in the P21/C space group as a dietherate with a = 9.208(3) ?, b = 14.353(4) ?, c = 12.805(4) ? and β = 98.64(3)° and contained terminal O and Cl atom disorder. The two crystallographically identical molybdenum centers are in distorted octahedral environments. Complexes were analyzed by IR, 31P NMR and X-ray crystallography. 相似文献103.
The objectives are to study and model the aggregate wind power fluctuations dynamics in the multifractal framework. We present here the analysis of aggregate power output sampled at 1 Hz during three years. We decompose the data into several Intrinsic Mode Functions (IMFs) using Empirical Mode Decomposition (EMD). We use a new approach, arbitrary order Hilbert spectral analysis, a combination of the EMD approach with Hilbert spectral analysis (or Hilbert–Huang Transform) and the classical structure-function analysis to extract the scaling exponents or multifractal spectrum ζ(q): this function provides a full characterization of a process at all intensities and all scales. The application of both methods, i.e. structure-function and arbitrary-order Hilbert spectral analyses, gives similar results indicating that the aggregate power output from a wind farm, possesses intermittent and multifractal properties. In order to check this result, we generate stochastic simulations of a Multifractal Random Walk (MRW) using a log-normal stochastic equation. We show that the simulation results are fully compatible with the experimental results. 相似文献
104.
Marcin Bilski Wojciech Kucharz Anna Valette Guillaume Valette 《Mathematische Zeitschrift》2013,275(1-2):403-418
Let $X$ be a compact nonsingular affine real algebraic variety. We prove that every pre-algebraic vector bundle on $X$ becomes algebraic after finitely many blowing ups. Using this theorem, we then prove that the Stiefel-Whitney classes of any pre-algebraic $\mathbb{R }$ -vector bundle on $X$ are algebraic. We also derive that the Chern classes of any pre-algebraic $\mathbb{C }$ -vector bundles and the Pontryagin classes of any pre-algebraic $\mathbb{R }$ -vector bundle are blow- $\mathbb{C }$ -algebraic. We also provide several results on line bundles on $X$ . 相似文献
105.
A. S. Hoover M. K. Bacrania N. J. Hoteling P. J. Karpius M. W. Rabin C. R. Rudy D. T. Vo J. A. Beall D. A. Bennett W. B. Doriese G. C. Hilton R. D. Horansky K. D. Irwin J. N. Ullom L. R. Vale 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(1):227-232
Microcalorimeter detectors provide superior energy resolution for the detection of X-rays and gamma-rays. The technology utilizes a cryogenic transition-edge sensor (TES) coupled to a tin bulk absorber. We are working on fabrication methods for the production of arrays with many sensors. In this paper, we present data collected with an array of microcalorimeters using as many as 26 sensor elements simultaneously. Advances in sensor design have extended the useful dynamic range to photon energies up to ~200 keV, while providing resolution performance in the 80–90 eV FWHM range, significantly better than planar high-purity germanium. These sensor arrays have applications in the measurement of nuclear materials. We present data collected from 153Gd, a highly-enriched uranium sample, and a plutonium isotopic standard source. We also demonstrate clean separation of the 235U 185.715 keV peak from the ubiquitous 226Ra 186.211 keV background peak interference. 相似文献
106.
A model experiment for the study of evaporating turbulent two-phase flows is presented here. The study focuses on a situation
where pre-atomized and dispersed droplets vaporize and mix in a heated turbulent flow. The test bench consists in a channel
flow with characteristics of homogeneous and isotropic turbulence where fluctuations levels reach very high values (25% in
the established zone). An ultrasonic atomizer allows the injection of a mist of small droplets of acetone in the carrier flow.
The large range diameters ensure that every kind of droplet behavior with regards to turbulence is possible. Instantaneous
concentration fields of the vaporized phase are extracted from fluorescent images (PLIF) of the two phase flow. The evolution
of the mixing of the acetone vapor is analyzed for two different liquid mass loadings. Despite the high turbulence levels,
concentration fluctuations remain significant, indicating that air and acetone vapor are not fully mixed far from the injector. 相似文献
107.
Yanina V. Burgart Galina F. Makhaeva Olga P. Krasnykh Sophia S. Borisevich Natalia A. Agafonova Nadezhda V. Kovaleva Natalia P. Boltneva Elena V. Rudakova Evgeny V. Shchegolkov Galina A. Triandafilova Denis A. Gazizov Olga G. Serebryakova Maria V. Ulitko Sergey L. Khursan Victor I. Saloutin Rudy J. Richardson 《Molecules (Basel, Switzerland)》2022,27(22)
One of the powerful antioxidants used clinically is Edaravone (EDA). We synthesized a series of new EDA analogs, 4-aminopyrazol-5-ol hydrochlorides, including polyfluoroalkyl derivatives, via the reduction of 4-hydroxyiminopyrazol-5-ones. The primary antioxidant activity of the compounds in comparison with EDA was investigated in vitro using ABTS, FRAP, and ORAC tests. In all tests, 4-Amino-3-pyrazol-5-ols were effective. The lead compound, 4-amino-3-methyl-1-phenylpyrazol-5-ol hydrochloride (APH), showed the following activities: ABTS, 0.93 TEAC; FRAP, 0.98 TE; and ORAC, 4.39 TE. APH and its NH-analog were not cytotoxic against cultured normal human fibroblasts even at 100 μM, in contrast to EDA. According to QM calculations, 4-aminopyrazolols were characterized by lower gaps, IP, and η compared to 4-hydroxyiminopyrazol-5-ones, consistent with their higher antioxidant activities in ABTS and FRAP tests, realized by the SET mechanism. The radical-scavenging action evaluated in the ORAC test occurred by the HAT mechanism through OH bond breaking in all compounds, directly dependent on the dissociation energy of the OH bond. All the studied compounds demonstrated the absence of anticholinesterase activity and moderate inhibition of CES by some 4-aminopyrazolols. Thus, the lead compound APH was found to be a good antioxidant with the potential to be developed as a novel therapeutic drug candidate in the treatment of diseases associated with oxidative stress. 相似文献
108.
109.
110.
L. Jarczyk B. Kamys Z. Rudy A. Strzalkowski B. Styczeń G. P. A. Berg A. Magiera J. Meißburger W. Oelert P. von Rossen J. G. M. Römer J. L. Tain H. H. Wolter E. Kwaśniewicz 《Zeitschrift für Physik A Hadrons and Nuclei》1986,325(3):303-308
Angular distributions of the12C(d,7Li)7Be reaction to the ground and to the unresolved first excited states of7Li or7Be nuclei were measured in the entire angular region in the centre of mass system atE lab=78.0 MeV. Both the one-step five-nucleon cluster transfer as well as two-step sequential transfers were considered in the theoretical analysis. The former mechanism was found to dominate, but the latter is also not negligible. 相似文献