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91.
Ecklund KM Love W Savinov V Lopez A Mendez H Ramirez J Ge JY Miller DH Shipsey IP Xin B Adams GS Anderson M Cummings JP Danko I Hu D Moziak B Napolitano J He Q Insler J Muramatsu H Park CS Thorndike EH Yang F Artuso M Blusk S Khalil S Li J Mountain R Nisar S Randrianarivony K Sultana N Skwarnicki T Stone S Wang JC Zhang LM Bonvicini G Cinabro D Dubrovin M Lincoln A Rademacker J Asner DM Edwards KW Naik P Reed J Briere RA Ferguson T Tatishvili G Vogel H Watkins ME Rosner JL Alexander JP 《Physical review letters》2008,100(16):161801
Using a sample of tagged D(s)(+) decays collected near the D(s)(*+/-)D(s)(-/+) peak production energy in e(+)e(-) collisions with the CLEO-c detector, we study the leptonic decay D(s)(+)-->tau(+)nu(tau) via the decay channel tau(+)-->e(+)nu(e)nu(tau). We measure B(D(s)(+)-->tau(+)nu(tau))=(6.17+/-0.71+/-0.34)%, where the first error is statistical and the second systematic. Combining this result with our measurements of D(s)(+)-->mu(+)nu(mu) and D(s)(+)-->tau(+)nu(tau) (via tau(+)-->pi(+)nu(tau)), we determine f(D(s))=(274+/-10+/-5) MeV. 相似文献
92.
Lincoln Chayes Nicholas Crawford Dmitry Ioffe Anna Levit 《Journal of statistical physics》2008,133(1):131-149
This paper studies a generalization of the Curie-Weiss model (the Ising model on a complete graph) to quantum mechanics. Using a natural probabilistic representation of this model, we give a complete picture of the phase diagram of the model in the parameters of inverse temperature and transverse field strength. Further analysis computes the critical exponent for the vanishing of the order parameter in the approach to the critical curve and gives useful stability properties for a variational problem associated with the representation. 相似文献
93.
We report that organic semiconductors such as alpha-sexithiophene (alpha-6T) have magnetoresistance (MR) with unexpected sign changes; depending on applied voltage, temperature, and layer thickness, the resistance may either increase or decrease upon application of a small magnetic field (<100 mT). We propose that MR and the inversion of MR are due to the role of hyperfine interaction in a magnetic field, as illustrated by the recombination-limited regime. 相似文献
94.
95.
Karl Eberhard Bessler Lincoln Lucílio Romualdo Paulo de Tarso Salviano Filho Victor Marcelo Deflon Ccilia Maichle‐Mssmer 《无机化学与普通化学杂志》2001,627(4):651-654
Preparation and Crystal Structures of Dicyanamido(triphenylphosphane)gold(I) and Nitrosodicyanomethanido(triphenylphosphane)gold(I) The coordination compounds [(Ph3P)Au{N(CN)2}] ( 1 ) and [(Ph3P)Au{ONC(CN)2}] ( 2 ) are obtained by the reaction of [Au(PPh3)]NO3 with Na[N(CN)2] or K[ONC(CN)2] in CH2Cl2. The compounds are characterized by IR spectroscopy and by crystal structure determination. 1 crystallizes triclinic in the space group P 1 with a = 930.16(4), b = 1011.89(13), c = 1118.35(16) pm, α = 115.327(10), β = 90.899(8), γ = 103.394(8)°, Z = 2. 2 crystallizes monoclinic in the space group P21/n with a = 832.59(10), b = 1139.30(16), c = 2078.9(4) pm, β = 99.84(2)°, Z = 4. The crystal structures of both compounds are built up by pairs of antiparallel oriented molecules with linear coordinated gold atoms and weak intermolecular Au–N‐interactions. 相似文献
96.
Lincoln Wolfenstein 《Nuclear Physics B》1980,175(1):93-96
We develop the consequences of a model for neutrino oscillations due to Zee involving extra Higgs bosons. The model leads naturally to large amplitude oscillations. 相似文献
97.
98.
The low temperature structure of C6F5PCl4 was confirmed by 35Cl NQR measurements as ψ-trigonal bipyramidal, with the C6F5 group axial. Discrepancies were found with previously reported data, possible causes of these are discussed. 相似文献
99.
In the long succession of small transition-metal compounds interacting reversibly with DNA, semirigid binuclear ruthenium complexes stand out by displaying exceptionally slow binding kinetics. To reach the final intercalated state, one of the bulky metal centers has to be threaded through the base stack, leading to a high level of structural discrimination. This makes the idea of utilizing binuclear complexes interesting in applications involving DNA sequence or conformation recognition. The finding that threading intercalation of the two structural analogues, Lambda,Lambda-[mu-(11,11'-bidppz)X4Ru2]4+, X = 2,2'-bipyridine (Lambda,Lambda-B4) and X = 1,10'-phenanthroline (Lambda,Lambda-P4), into poly(dA-dT)2 can be described by surprisingly simple rate laws encouraged more extensive studies and analysis of these two systems. Kinetic measurements at different [basepair]/[complex] ratios show that Lambda,Lambda-B4 intercalates via a pseudo-first-order mechanism independent of binding density, whereas Lambda,Lambda-P4 displays a gradual transition from apparent first- to second-order kinetics when decreasing the [basepair]/[complex] mixing ratio. By employing the probabilistic method of McGhee and von Hippel, a rate law based on a supposed mechanism has been globally fitted and numerically integrated to describe threading of Lambda,Lambda-P4. In contrast to Lambda,Lambda-B4, the first-order mechanism of this analogue appears to require a long stretch of nonthreaded DNA. The results show that ancillary ligand structures indeed affect the mechanism of DNA threading, demonstrating the potential use of semirigid binuclear ruthenium complexes to target DNA. 相似文献
100.
Amira Abou-Hamdan Ian M. Brereton Andrea M. Hounslow Stephen F. Lincoln Thomas M. Spotswood 《Journal of inclusion phenomena and macrocyclic chemistry》1987,5(2):137-141
In the solid and solution state Li+ and Na+ form inclusive and exclusive cryptates respectively with C21C5, in which Li+ resides inside and Na+ resides outside the C21C5 cavity. Similar inclusive and exclusive structures are observed for [Li.C211]+ and [Na. C211]+. The logarithms of the stability constants in dimethylformamide for [Li.C21C5]+, [Li.C211]+, [Na.C21C5]+ and [Na.C211]+ are: 2.80, 6.99, 2.87 and 5.20; ando the corresponding decomplexation rate constants are: 107, 0.013, 28800 and 12 s–1 at 298.2 K. The relationships between cryptate structure, stability and lability are considered, as are solvent influences. 相似文献