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41.
Marjorie C. L. C. Freire Gabriela D. Noske Natlia V. Bitencourt Paulo R. S. Sanches Norival A. Santos-Filho Victor O. Gawriljuk Eduardo P. de Souza Victor H. R. Nogueira Mariana O. de Godoy Aline M. Nakamura Rafaela S. Fernandes Andre S. Godoy Maria A. Juliano Bianca M. Peres Cecília G. Barbosa Carolina B. Moraes Lucio H. G. Freitas-Junior Eduardo M. Cilli Rafael V. C. Guido Glaucius Oliva 《Molecules (Basel, Switzerland)》2021,26(16)
The COVID-19 outbreak has rapidly spread on a global scale, affecting the economy and public health systems throughout the world. In recent years, peptide-based therapeutics have been widely studied and developed to treat infectious diseases, including viral infections. Herein, the antiviral effects of the lysine linked dimer des-Cys11, Lys12,Lys13-(pBthTX-I)2K ((pBthTX-I)2K)) and derivatives against SARS-CoV-2 are reported. The lead peptide (pBthTX-I)2K and derivatives showed attractive inhibitory activities against SARS-CoV-2 (EC50 = 28–65 µM) and mostly low cytotoxic effect (CC50 > 100 µM). To shed light on the mechanism of action underlying the peptides’ antiviral activity, the Main Protease (Mpro) and Papain-Like protease (PLpro) inhibitory activities of the peptides were assessed. The synthetic peptides showed PLpro inhibition potencies (IC50s = 1.0–3.5 µM) and binding affinities (Kd = 0.9–7 µM) at the low micromolar range but poor inhibitory activity against Mpro (IC50 > 10 µM). The modeled binding mode of a representative peptide of the series indicated that the compound blocked the entry of the PLpro substrate toward the protease catalytic cleft. Our findings indicated that non-toxic dimeric peptides derived from the Bothropstoxin-I have attractive cellular and enzymatic inhibitory activities, thereby suggesting that they are promising prototypes for the discovery and development of new drugs against SARS-CoV-2 infection. 相似文献
42.
We consider Glauber dynamics for the Ising model on the complete graph on n vertices, known as the Curie-Weiss model. It is well-known that the mixing-time in the high temperature regime (β < 1) has order n log n, whereas the mixing-time in the case β > 1 is exponential in n. Recently, Levin, Luczak and Peres proved that for any fixed β < 1 there is cutoff at time with a window of order n, whereas the mixing-time at the critical temperature β = 1 is Θ(n
3/2). It is natural to ask how the mixing-time transitions from Θ(n log n) to Θ(n
3/2) and finally to exp (Θ(n)). That is, how does the mixing-time behave when β = β(n) is allowed to tend to 1 as n → ∞. In this work, we obtain a complete characterization of the mixing-time of the dynamics as a function of the temperature,
as it approaches its critical point β
c
= 1. In particular, we find a scaling window of order around the critical temperature. In the high temperature regime, β = 1 − δ for some 0 < δ < 1 so that δ
2
n → ∞ with n, the mixing-time has order (n/δ) log(δ
2
n), and exhibits cutoff with constant and window size n/δ. In the critical window, β = 1± δ, where δ
2
n is O(1), there is no cutoff, and the mixing-time has order n
3/2. At low temperature, β = 1 + δ for δ > 0 with δ
2
n → ∞ and δ = o(1), there is no cutoff, and the mixing time has order .
Research of J. Ding and Y. Peres was supported in part by NSF grant DMS-0605166. 相似文献
43.
The rotor-router model is a deterministic analogue of random walk. It can be used to define a deterministic growth model analogous
to internal DLA. We prove that the asymptotic shape of this model is a Euclidean ball, in a sense which is stronger than our
earlier work (Levine and Peres, Indiana Univ Math J 57(1):431–450, 2008). For the shape consisting of sites, where ω
d
is the volume of the unit ball in , we show that the inradius of the set of occupied sites is at least r − O(logr), while the outradius is at most r + O(r
α
) for any α > 1 − 1/d. For a related model, the divisible sandpile, we show that the domain of occupied sites is a Euclidean ball with error in the radius a constant independent of the total
mass. For the classical abelian sandpile model in two dimensions, with n = πr
2 particles, we show that the inradius is at least , and the outradius is at most . This improves on bounds of Le Borgne and Rossin. Similar bounds apply in higher dimensions, improving on bounds of Fey and
Redig.
Yuval Peres is partially supported by NSF grant DMS-0605166. 相似文献
44.
In the heat-bath Glauber dynamics for the Ising model on the lattice, physicists believe that the spectral gap of the continuous-time
chain exhibits the following behavior. For some critical inverse-temperature β
c
, the inverse-gap is O(1) for β < β
c
, polynomial in the surface area for β = β
c
and exponential in it for β > β
c
. This has been proved for
\mathbbZ2{\mathbb{Z}^2} except at criticality. So far, the only underlying geometry where the critical behavior has been confirmed is the complete
graph. Recently, the dynamics for the Ising model on a regular tree, also known as the Bethe lattice, has been intensively
studied. The facts that the inverse-gap is bounded for β < β
c
and exponential for β > β
c
were established, where β
c
is the critical spin-glass parameter, and the tree-height h plays the role of the surface area.
In this work, we complete the picture for the inverse-gap of the Ising model on the b-ary tree, by showing that it is indeed polynomial in h at criticality. The degree of our polynomial bound does not depend on b, and furthermore, this result holds under any boundary condition. We also obtain analogous bounds for the mixing-time of
the chain. In addition, we study the near critical behavior, and show that for β > β
c
, the inverse-gap and mixing-time are both exp[Θ((β − β
c
)h)]. 相似文献
45.
We argue, for a wide class of systems including graphene, that in the low temperature, high density, large separation and strong screening limits the drag resistivity behaves as d(-4), where d is the separation between the two layers. The results are independent of the energy dispersion relation, the dependence on momentum of the transport time, and the electronic wave function structure. We discuss how a correct treatment of the electron-electron interactions in an inhomogeneous dielectric background changes the theoretical analysis of the experimental drag results of Kim et?al (2011 Phys. Rev. B 83 161401). We find that a quantitative understanding of the available experimental data (Kim et?al 2011 Phys. Rev. B 83 161401) for drag in graphene is lacking. 相似文献
46.
Denote by µ a the distribution of the random sum \((1 - a)\sum\nolimits_{j = 0}^\infty {{w_j}{a^j}} \), where P(ω j = 0) = P(ω j = 1) = 1/2 and all the choices are independent. For 0 < a < 1/2, the measure µ a is supported on C a , the central Cantor set obtained by starting with the closed united interval, removing an open central interval of length (1 ? 2a), and iterating this process inductively on each of the remaining intervals. We investigate the convolutions µ a * (µ b ° S λ ?1 ), where S λ (x) = λx is a rescaling map. We prove that if the ratio log b/ log a is irrational and λ ≠ 0, then , where D denotes any of correlation, Hausdorff or packing dimension of a measure.
We also show that, perhaps surprisingly, for uncountably many values of λ the convolution µ1/4* (µ1/3 ° S λ ?1 ) is a singular measure, although dim H (C 1/4) + dim H (C 1/3) > 1 and log(1/3)/ log(1/4) is irrational. 相似文献
$D({\mu _a} * ({\mu _b} \circ S_\lambda ^{ - 1})) = \min ({\dim _H}({C_a}) + {\dim _H}({C_b}),1)$
47.
Kinney and Pitcher (1966) determined the dimension of measures on [0, 1] which make the digits in the continued fraction expansion
i.i.d. variables. From their formula it is not clear that these dimensions are less than 1, but this follows from the thermodynamic
formalism for the Gauss map developed by Walters (1978). We prove that, in fact, these dimensions are bounded by 1−10−7. More generally, we considerf-expansions with a corresponding absolutely continuous measureμ under which the digits form a stationary process. Denote byE
δ the set of reals where the asymptotic frequency of some digit in thef-expansion differs by at leastδ from the frequency prescribed byμ. ThenE
δ has Hausdorff dimension less than 1 for anyδ>0. 相似文献
48.
M. Peres A. Cruz S. Pereira M.R. Correia M.J. Soares A. Neves M.C. Carmo T. Monteiro A.S. Pereira M.A. Martins T. Trindade E. Alves S.S. Nobre R.A. Sá Ferreira 《Applied Physics A: Materials Science & Processing》2007,88(1):129-133
Synthetic ZnO nanocrystals have been intentionally doped with Eu3+ ions. Structural analysis performed on the nanocrystals showed wurtzite-ZnO as the only phase present in the samples. Photoluminescence
in emission and excitation modes allows the assignment of the intra-4f6 transitions for the Eu3+ ions. From the analysis of the optical data we are able to demonstrate that multiple Eu-related optical centres are present
in the studied samples. Oxygen vacancies are likely candidates to be responsible for the ion accommodation in the ZnO lattice
and from the photoluminescence excitation data we tentatively assign a trap level at ∼200 meV below the conduction band to
this intrinsic defect.
PACS 78.66.Hf; 78.67.-n; 82.80.Yc 相似文献
49.
Asher Peres 《Foundations of Physics》1984,14(11):1131-1145
This paper contains four new dialogues among Simplicio, Salviati, and Sagredo, on the fate of Schrödinger's cat, the existence of physical quantities, the paradigm of Einstein, Podolsky, and Rosen, and why a watched kettle may boil, after all.Dedicated to Nathan Rosen, teacher and friend, on the occasion of his 75th birthday. 相似文献
50.
The number of infinite clusters in dynamical percolation 总被引:2,自引:2,他引:0
Summary. Dynamical percolation is a Markov process on the space of subgraphs of a given graph, that has the usual percolation measure
as its stationary distribution. In previous work with O. H?ggstr?m, we found conditions for existence of infinite clusters
at exceptional times. Here we show that for ℤ
d
, with p>p
c
, a.s. simultaneously for all times there is a unique infinite cluster, and the density of this cluster is θ(p). For dynamical percolation on a general tree Γ, we show that for p>p
c
, a.s. there are infinitely many infinite clusters at all times. At the critical value p=p
c
, the number of infinite clusters may vary, and exhibits surprisingly rich behaviour. For spherically symmetric trees, we
find the Hausdorff dimension of the set T
k
of times where the number of infinite clusters is k, and obtain sharp capacity criteria for a given time set to intersect T
k
. The proof of this capacity criterion is based on a new kernel truncation technique.
Received: 5 May 1997 / In revised form: 24 November 1997 相似文献