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151.
152.
Enrique Gil de Montes Alena Istrate Claudio D. Navo Ester Jimnez‐Moreno Emily A. Hoyt Francisco Corzana Inmaculada Robina Gonzalo Jimnez‐Oss Antonio J. Moreno‐Vargas Gonalo J. L. Bernardes 《Angewandte Chemie (International ed. in English)》2020,59(15):6196-6200
An azanorbornadiene bromovinyl sulfone reagent for cysteine‐selective bioconjugation has been developed. Subsequent reaction with dipyridyl tetrazine leads to bond cleavage and formation of a pyrrole‐linked conjugate. The latter involves ligation of the tetrazine to the azanorbornadiene‐tagged protein through inverse electron demand Diels–Alder cycloaddition with subsequent double retro‐Diels–Alder reactions to form a stable pyrrole linkage. The sequence of site‐selective bioconjugation followed by bioorthogonal bond cleavage was efficiently employed for the labelling of three different proteins. This method benefits from easy preparation of these reagents, selectivity for cysteine, and stability after reaction with a commercial tetrazine, which has potential for the routine preparation of protein conjugates for chemical biology studies. 相似文献
153.
Elena de las Heras Ester Boix-Garriga Francesca Bryden Montserrat Agut Margarita Mora M. Lluïsa Sagristá Ross W. Boyle Norbert Lange Santi Nonell 《Photochemistry and photobiology》2020,96(3):570-580
Active targeting strategies are currently being extensively investigated in order to enhance the selectivity of photodynamic therapy. The aim of the present research was to evaluate whether the external decoration of nanopolymeric carriers with targeting peptides could add more value to a photosensitizer formulation and increase antitumor therapeutic efficacy and selectivity. To this end, we assessed PLGA-PLA-PEG nanoparticles (NPs) covalently attached to a hydrophilic photosensitizer 5-[4-azidophenyl]-10,15,20-tri-(N-methyl-4-pyridinium)porphyrinato zinc (II) trichloride (ZnTriMPyP) and also to c(RGDfK) peptides, in order to target αvβ3 integrin-expressing cells. In vitro phototoxicity investigations showed that the ZnTriMPyP-PLGA-PLA-PEG-c(RGDfK) nanosystem is effective at submicromolar concentrations, is devoid of dark toxicity, successfully targets αvβ3 integrin-expressing cells and is 10-fold more potent than related nanosystems where the PS is occluded instead of covalently bound. 相似文献
154.
Abhik Kumar Sanyal Claudio Rubano Ester Piedipalumbo 《General Relativity and Gravitation》2011,43(10):2807-2820
Noether symmetry for Gauss–Bonnet Dilatonic interaction exists for a constant dilatonic scalar potential and a linear functional
dependence of the coupling parameter on the scalar field. The symmetry with the same form of the potential and coupling parameter
exists all in the vacuum, radiation and matter dominated era. The late time acceleration is driven by the effective cosmological
constant rather than the Gauss–Bonnet term, while the later compensates for the large value of the effective cosmological
constant giving a plausible answer to the well-known coincidence problem. 相似文献
155.
156.
Let μ
0 be a probability measure on ℝ3 representing an initial velocity distribution for the spatially homogeneous Boltzmann equation for pseudo Maxwellian molecules.
As long as the initial energy is finite, the solution μ
t
will tend to a Maxwellian limit. We show here that if
, then instead, all of the mass “explodes to infinity” at a rate governed by the tail behavior of μ
0. Specifically, for L0, define
Let B
R
denote the centered ball of radius R. Then for every R,
The explicit rate is estimated in terms of the rate of divergence of η
L
. For example, if η
L
≥Const.L
s
, some s>0,
is bounded by a multiple of e
−[κ3s/(10+9s)]t
, where κ is the absolute value of the spectral gap in the linearized collision operator. Note that in this case, letting B
t
denote the ball of radius e
rt
for any r<κ
s/(10+9s), we still have
.
This result shows in particular that the necessary and sufficient condition for lim
t→∞
μ
t
to exist is that the initial data have finite energy. While the “explosion” of the mass towards infinity in the case of infinite
energy may seem to be intuitively clear, there seems not to have been any proof, even without the rate information that our
proof provides, apart from an analogous result, due to the authors, concerning the Kac equation. A class of infinite energy
eternal solutions of the Boltzmann equation have been studied recently by Bobylev and Cercignani. Our rate information is
shown here to provide a limit on the tails of such eternal solutions.
E. Carlen’s work is partially supported by U.S. National Science Foundation grant DMS 06-00037.
E. Gabetta’s and E. Regazzini’s work is partially supported by Cofin 2004 “Probleme matematici delle teorie cinetiche” (MIUR). 相似文献
157.
A topologically extended model of a chemically cross-linked hydrogel of poly(vinyl alcohol) (PVA) at high hydration degree has been developed for a molecular dynamics simulation with atomic detail at 323 K. The analysis of the 5 ns trajectory discloses structural and dynamic aspects of polymer solvation and elucidates the water hydrogen bonding and diffusion in the network. The features of local polymer dynamics indicate that PVA mobility is not affected by structural constraints of chemical junctions at the investigated cross-linking density, with a prevailing dumping effect due to water interaction. Simulation results are validated by a favorable comparison with findings of an incoherent quasi-elastic neutron scattering study of the same hydrogel system. 相似文献
158.
Although there is increasing concern about residues from personal care products entering the aquatic environment and their
potential to accumulate to levels that pose a health threat to humans and wildlife, we still know little about the extent
and magnitude of their presence in the aquatic environment. In this study we describe a procedure for isolation, and subsequent
determination, of compounds commonly added to personal care products. The compounds of interest include UV filters with the
commercial name Eusolex (homosalate, 4-methylbenzylidenecamphor, benzophenone-3, octocrylene, butylmethoxydibenzoylmethane,
ethylhexyl methoxycinnamate) and two common anti-microbial agents, clorophene and triclosan. Water samples were filtered,
acidified, and extracted by use of solid-phase extraction. Extracted compounds were then derivatised before analysis by gas
chromatography–mass spectroscopy. By use of our method we obtained limits of detection of 13–266 ng L−1 for UV filters, and 10–186 ng L−1 for triclosan and clorophene. Recoveries were 82–98% for deionised water and 50–98% for natural water (seawater, pool water,
lake water, and river water). Samples collected in Slovenia included seventeen recreational waters (seawater, pool water,
lake water, and river water; August 2004) and four wastewaters (January 2005). The most abundant UV filter was benzophenone-3
(11–400 ng L−1). Of the two anti-microbial agents studied, trace amounts, only, of triclosan were present in the river Kolpa (68 ng L−1) and in an hospital effluent (122 ng L−1). 相似文献
159.
Chelo Ferreira José L. López Ester Pérez Sinusía 《Mediterranean Journal of Mathematics》2013,10(4):1853-1865
We consider the Mellin convolution integral representation of the second Appell function given in [8]. Then, we apply the asymptotic method designed in [12] for this kind of integrals to derive new asymptotic expansions of the Appell function F 2 for one large variable in terms of hypergeometric functions. For certain values of the parameters, some of these expansions involve logarithmic terms in the asymptotic variables. The accuracy of the approximations is illustrated with numerical experiments. 相似文献
160.