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161.
Debosreeta Bose Deboleena Sarkar Nitin Chattopadhyay 《Photochemistry and photobiology》2010,86(3):538-544
In the present investigation, an attempt has been made to study the interaction of phenosafranin (PSF), a cationic phenazinium dye with the transport proteins, bovine serum albumin (BSA) and human serum albumin (HSA), employing steady-state and time-resolved fluorometric and circular dichroism (CD) techniques. The photophysical properties of the dye are altered on binding with the serum proteins. An explicit study with respect to the modification of the fluorescence and fluorescence anisotropy upon binding, effect of denaturant, fluorescence lifetime and CD measurements reveal that the dye binds to both BSA and HSA with almost the same affinity. Far-UV CD spectra indicate a decrease in the percentage of α-helicity only for BSA upon binding with the probe. Near-UV CD responses indicate an alteration in the tertiary structure of both the transport proteins because of binding. 相似文献
162.
163.
A convenient access to substituted benzothiazole scaffolds via intramolecular cyclization of thioformanilides 总被引:1,自引:0,他引:1
A new and practical method has been developed for the synthesis of substituted benzothiazoles via the intramolecular cyclization of thioformanilides using DDQ in CH2Cl2 at ambient temperature. The reaction proceeds in high yields via the thiyl radical to give novel oxybis-benzothiazole, and offers a high degree of flexibility with regard to the functional groups that can be placed on the benzothiazole nucleus or 2-aryl moiety which in turn generates scaffolds for parallel synthesis. 相似文献
164.
Treatment of group 5 metal polychlorides such as, [CpnMCl4-x] (M = V: n, x = 2; M = Nb: n = 1, x = 0), or [Cp∗TaCl4] (Cp = η5-C5H5, Cp∗ = η5-C5Me5), with [LiBH4·THF] followed by thermolysis in the presence of diphenyl diselenide yielded metallaheteroborane clusters [{CpV(μ-SePh)}2(μ-Se)], 1 [(CpNb)2B4H9(μ-SePh)], 2 and [(Cp∗Ta)2B4H11(SePh)], 3 in modest yields. Compound 1 is an organovanadium selenolato cluster in which two (CpV) moieties bridged by (μ-Se) and two (μ-SePh) ligands. Compound 2 exhibits a bicapped tetrahedral core with one (μ-SePh) ligand. 3 is a tantalahexaborane cluster in which one of the terminal BH protons is substituted by SePh. Compounds 1-3 have been characterized by mass spectrometry, 1H, 11B, 13C NMR spectroscopy, and the geometric structures were unequivocally established by crystallographic analysis of 1-3. 相似文献
165.
We report here a methodology of chemo- and regio-selective aryl bromination and iodination using respective N-halosuccinimides at room temperature in the absence of any solvents, catalyst/additives under ball-milling condition. However, for chlorination ceric ammonium nitrate was used as additive. The coupled product succinimide, produced from the reactions, was recycled via regeneration of NBS. This methodology works with the electron-donor substituted or unsubstituted arenes. 相似文献
166.
We formulate the data analysis problem for the detection of the Newtonian coalescing-binary signal by a network of laser interferometric
gravitational wave detectors that have arbitrary orientations, but are located at the same site. We use the maximum likelihood
method for optimizing the detection problem. We show that for networks comprising of up to three detectors, the optimal statistic
is just the matched network-filter. Alternatively, it is simply a linear combination of the signal-to-noise ratios of the
individual detectors. This statistic, therefore, can be interpreted as the signal-to-noise ratio of the network. The overall
sensitivity of the network is shown to increase roughly as the square-root of the number of detectors in the network. We further
show that these results continue to hold even for the restricted post-Newtonian filters. Finally, our formalism is general
enough to be extended, in a straightforward way, to address the problem of detection of such waves from other sources by some
other types of detectors, eg., bars or spheres, or even by networks of spatially well-separated detectors. 相似文献
167.
168.
A. Bose 《Applied Surface Science》2010,256(21):6205-6212
PZT thin films of thickness (320-1040) nm were synthesized on Si/SiO2/Ti/Pt multilayered substrates by radio frequency magnetron sputtering. The influence of plasma pressure in the range of (0.24-4.9) Pa, during deposition, on the structural, electrical and ferroelectric properties of the PZT films was systematically studied. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and cross-sectional transmission electron microscopy (XTEM) were employed for structural study. Nano-probe Energy Dispersive (EDX) line scanning was employed to investigate the elemental distribution across the film-bottom electrode interface. I-V characteristics and polarization-electric field (P-E) hysteresis loop of the films were measured. The study reveals that the plasma pressure has a strong influence on the evolution and texture of the ferroelectric perovskite phase and microstructure of the films. At an optimum plasma pressure of 4.1 Pa, PZT films are grown with 93% perovskite phase with (1 1 1) preferred orientation and uniform granular microstructure. These films show a saturation polarization of 67 μC/cm2, remnant polarization of 30 μC/cm2 and coercive field of 28 kV/cm which, according to the literature, seem to be suitable for device applications.Transmission electron microscopy (TEM) study shows that at a plasma pressure of 4.1 Pa, the PZT/bottom Pt interface is sharp and no amorphous interlayer is formed at the interface. At a higher plasma pressure of 4.9 Pa, poor I-V and P-E hysteresis loop are observed which are interpreted as due to an amorphous interlayer at the film-bottom electrode interface which is possibly enriched in Pb, Zr, O and Pt. 相似文献
169.
We formulate a modified theory of gravity to an equivalent second order gravity theory for a Lagrangian containing R and
\frac1R{\frac{1}{R}} terms by introducing an auxiliary variable in a spatially homogeneous and isotropic background. We present a few analytical
solutions of evolution equation for the deceleration parameter q as a function of the scale factor; specially in one solution, the universe evolves continuously from q = 1 (i.e. like a radiation dominated era) to
q = -\frac12{q= -\frac{1}{2}} dark energy dominated late time accelerating phase when the universe is sufficiently old. The solution is supported by numerical
results. 相似文献
170.
Subash Chandra Bose Gopinath 《Analytica chimica acta》2009,636(2):117-18
RNA-protein interactions are important biological events that perform multiple functions in all living organisms. The wide range of RNA interactions demands diverse conformations to provide contacts for the selective recognition of proteins. Various analytical procedures are presently available for quantitative analyses of RNA-protein complexes, but analytical-based mapping of these complexes is essential to probe specific interactions. In this overview, interactions of functional RNAs and RNA-aptamers with target proteins are discussed by means of mapping strategies. 相似文献