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31.
Carmen Coll Elena Aznar Ramón Martínez‐Máñez Prof. M. Dolores Marcos Dr. Félix Sancenón Dr. Juan Soto Dr. Pedro Amorós Joan Cano Dr. Eliseo Ruiz Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(33):10048-10061
We report the preparation of a MCM‐41 mesoporous material that contains the dye [Ru(bipy)3]Cl2 (bipy=bipyridine) inside the mesopores and functionalised with suitable binding groups at the entrance of the pores. Solids S1 – S3 were obtained by the reaction of the mesoporous material with N‐methyl‐N′‐propyltrimethoxysilylimidazolium chloride, N‐phenyl‐N′‐[3‐(trimethoxysilyl)propyl]thiourea, or N‐phenyl‐N′‐[3‐(trimethoxysilyl)propyl]urea, respectively. A study of the dye delivery of these systems in buffered water (pH 7.0, 2‐[4‐(2‐hydroxyethyl)piperazin‐1‐yl]ethanesulfonic acid (HEPES), 10?3 mol dm?3) in the presence of a family of carboxylate ions was carried out. In the interaction of the anions with the surface of the solids, the response depends on the characteristics of the binding groups (i.e., imidazolium, urea and thiourea) at the pore outlets and their specific interaction with the corresponding anion. The interaction of long‐chain carboxylate ions with the binding sites at the surface of the solids resulted in a remarkable inhibition of the delivery of the dye. This inhibition was observed clearly for the dodecanoate anion, whereas the octanoate, decanoate, cholate, deoxycholate, glycodeoxycholate and taurocholate anions induced a certain pore blockage that varied according to the solid studied. The interaction of smaller anions, such as acetate, butanoate, hexanoate and octanoate, with the solids had no effect on the dye release process. The possible use of the gating system for the chromo‐fluorogenic detection of anionic surfactants through selective dye delivery inhibition was also explored. Molecular dynamic simulations that use force‐field methods have been made to theoretically study the capping carboxylate mechanism. The calculations are in agreement with the experimental results, thus allowing a representation of the dye delivery inhibition in the presence of long‐chain carboxylate ions. 相似文献
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Christiane Lorenz Harald Hagendorfer Natalie von Goetz Ralf Kaegi Robert Gehrig Andrea Ulrich Martin Scheringer Konrad Hungerbühler 《Journal of nanoparticle research》2011,13(8):3377-3391
Consumer spray products are already on the market in the cosmetics and household sector, which suggest by their label that
they contain engineered nanoparticles (ENP). Sprays are considered critical for human health, because the lungs represent
a major route for the uptake of ENP into the human body. To contribute to the exposure assessment of ENP in consumer spray
products, we analyzed ENP in four commercially available sprays: one antiperspirant, two shoe impregnation sprays, and one
plant-strengthening agent. The spray dispersions were analyzed by inductively coupled plasma mass spectrometry (ICPMS) and
(scanning-) transmission electron microscopy ((S)TEM). Aerosols were generated by using the original vessels, and analyzed
by scanning mobility particle sizer (SMPS) and (S)TEM. On the basis of SMPS results, the nanosized aerosol depositing in the
respiratory tract was modeled for female and male consumers. The derived exposure levels reflect a single spray application.
We identified ENP in the dispersions of two products (shoe impregnation and plant spray). Nanosized aerosols were observed
in three products that contained propellant gas. The aerosol number concentration increased linearly with the sprayed amount,
with the highest concentration resulting from the antiperspirant. Modeled aerosol exposure levels were in the range of 1010 nanosized aerosol components per person and application event for the antiperspirant and the impregnation sprays, with the
largest fraction of nanosized aerosol depositing in the alveolar region. Negligible exposure from the application of the plant
spray (pump spray) was observed. 相似文献
35.
We revisit the production of a single Higgs boson from direct γγ-scattering at a photon collider. We compute the total cross-section σ(γγ→h) (for h=h0,H0,A0), and the strength of the effective gh0γγ coupling normalized to the Standard Model (SM), for both the general Two-Higgs-Doublet Model (2HDM) and the Minimal Supersymmetric Standard Model (MSSM). In both cases the predicted production rates for the CP-even (odd) states render up to 104 (103) events per 500 fb−1 of integrated luminosity, in full consistency with all the theoretical and phenomenological constraints. Depending on the channel the maximum rates can be larger or smaller than the SM expectations, but in most of the parameter space they should be well measurable. We analyze how these departures depend on the dynamics underlying each of the models, supersymmetric and non-supersymmetric, and highlight the possible distinctive phenomenological signatures. We demonstrate that this process could be extremely useful to discern non-supersymmetric Higgs bosons from supersymmetric ones. Furthermore, in the MSSM case, we show that γγ-physics could decisively help to overcome the serious impasse afflicting Higgs boson physics at the infamous “LHC wedge”. 相似文献
36.
Alan Garbarz Joan La Madrid Mauricio Leston 《The European Physical Journal C - Particles and Fields》2017,77(11):807
We revisit the dynamics of a massive scalar field in a Banados, Teitelboim, and Zanelli background taking into account the lack of global hyperbolicity of the spacetime. We approach this issue using the strategy of Ishibashi and Wald which finds a unique smooth solution as the causal evolution of initial data, each possible evolution corresponding to a positive self-adjoint extension of certain operator in a Hilbert space on the initial surface. Moreover, solutions obtained this way are the most general ones satisfying a few physically sensible requirements. This procedure is intimately related to the choice of boundary conditions and the existence of bound states. We find that the scalar field dynamics in the (effective) mass window \(-3/4\le m_e^2\ell ^2<0\) can be well defined within a one-parametric family of distinct boundary conditions (\(-3/4\) being the conformally coupled case), while for \(m_e^2\ell ^2\ge 0\) the boundary condition is unique (only one self-adjoint extension is possible). It is argued that there is no sensible evolution possible for \(m_e^2\ell ^2<-1\), and also it is shown that in the range \(m_e^2\ell ^2 \in [-1,-3/4)\) there is a U(1) family of allowed boundary conditions, however, the positivity of the self-adjoint extensions is only motivated but not proven. We focus mainly on describing the dynamics of such evolutions given the initial data and all possible boundary conditions, and in particular we show the energy is always positive and conserved. 相似文献
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Sergio Peris Bartosz Tylkowski Joan Carles Ronda Ricard Garcia‐Valls José Antonio Reina Marta Giamberini 《Journal of polymer science. Part A, Polymer chemistry》2009,47(20):5426-5436
Two new polyethers, bearing azobenzene moiety in the side chain, were synthesized in excellent yields by means of anionic polymerization of 4‐glycidyloxyazobenzene and 4‐cyano‐4′‐glycidyloxyazobenzene (leading to azo‐P1 and azo‐P2 polymers, respectively) with the system polyiminophosphazene base t‐Bu‐P4/3,5‐di‐tert‐butylphenol as initiator. The polymers were characterized with respect to their molecular weights, structure, and calorimetric features. The polyether bearing cyanoazobenzene group in the side chain was found to exhibit nematic phase up to 200 °C. E–Z isomerization of both polymers in tetrahydrofuran solution, after irradiating with UV light at 364 nm for 15 min, was investigated by means of UV–visible absorption spectroscopy. In the case of glycidylic monomers as well as the resulting polymers, E–Z isomerization was also investigated by means of 1H NMR, by direct irradiation in the NMR probe in deuterated 1,1,2,2‐tetrachloroethane solution. By this technique, in the case of 4‐cyano‐4′‐glycidyloxyazobenzene, it was found that irradiation led to a photostationary state corresponding to an amount of Z isomer equal to 25%. For azo‐P1 polymer, Z–E or “reverse” isomerization was investigated at 60, 70, or 80 °C directly in the NMR probe; as expected, the process followed a first‐order rate law. The kinetic constants as well as the activation energy for the process were determined in this temperature range. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5426–5436, 2009 相似文献
40.
Joan F. Boyar Howard J. Karloff 《Journal of Algorithms in Cognition, Informatics and Logic》1987,8(4)
We present NC algorithms for vertex and edge coloring planar graphs. The vertex coloring algorithm 5 colors any planar graph, and the edge coloring algorithm Δ edge colors planar graphs with Δ ≥ 23 (and Δ + 1 edge colors planar graphs with Δ < 23), where Δ is the maximum degree in the graph. 相似文献