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The Schur basis on n d-dimensional quantum systems is a generalization of the total angular momentum basis that is useful for exploiting symmetry under permutations or collective unitary rotations. We present efficient {size poly[n,d,log(1/epsilon)] for accuracy epsilon} quantum circuits for the Schur transform, which is the change of basis between the computational and the Schur bases. Our circuits provide explicit efficient methods for solving such diverse problems as estimating the spectrum of a density operator, quantum hypothesis testing, and communicating without a shared reference frame. We thus render tractable a large series of methods for extracting resources from quantum systems and for numerous quantum information protocols. 相似文献
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85.
Mixing small molecule gelators is a promising route to prepare useful and exciting materials that cannot be accessed from any of the individual components. Here, we describe pH-triggered hydrogelation by mixing of two non-gelling amphiphiles. The intermolecular interactions among the molecules can be tuned either by controlling the degree of ionization of the components or by a preparative pathway, which enables us to control material properties such as gel strength, gel stiffness, thermal stability, and an unusual shrinking/swelling behaviour.The properties of a charge complementary multicomponent gel can be tuned either by pH change or by varying the preparative pathway. 相似文献
86.
J. S. Dave George Kljrian A. P. Prajapati 《Molecular Crystals and Liquid Crystals》2013,570(1):385-389
Compounds containing naphthalene moiety are synthesized and the liquid crystalline properties studied by texture observations. The mesomorphic properties of these compounds are compared with related compounds to understand the influence of broad units such as naphthalene on mesomorphism. It is observed that there is a limit to which the end alkoxy group can be extended in a mesogen. The method of preparation, and properties of these compounds are given. 相似文献
87.
Shantanu Dave 《Monatshefte für Mathematik》2013,170(2):121-145
We consider distributions on a closed compact manifold $M$ as maps on smoothing operators. Thus spaces of maps between ${{\Psi }^{\!-\!\infty }}(M)$ and $\mathcal{C ^{\infty }}(M)$ are considered as generalized functions. For any collection of regularizing processes we produce various algebras of generalized functions and equivariant embeddings of distributions into such algebras. The regularity for such generalized functions is provided in terms of a certain tameness of maps between graded Frechét spaces. This also recovers the singularity behaviour of distributions (singular support/wavefront sets) in terms of certain subalgebras of the algebra of generalized functions. This notion of regularity is compared with the regularity in Colombeau algebras in the $\mathcal{G }^{\infty }$ sense. 相似文献
88.
Eric Shinn Alfred Hübler Dave Lyon Matthias Grosse Perdekamp Alexey Bezryadin Andrey Belkin 《Complexity》2013,18(3):24-27
The efficiency of conventional techniques used to harvest energy in nuclear reactors lies around 35%. This limit exists, because the nuclear energy is converted to electrical energy via heat engines. We study an alternative approach where the kinetic energy of nuclear reaction products is directly converted into electric energy in a stack of charged capacitors with a gap size of 500 nm and graphene electrodes. Graphene is expected to be chemically and mechanically stable in high‐radiation environments, because its tensile strength of 130 GPa is very large, about 100 times larger than most metals. The dielectric strength of such nanocapacitors exceeds 1 GV/m, because avalanching is suppressed at small gap sizes. In a 1 GV/m electric field charged nuclear reaction products, such as 5.6 MeV alpha particles, come to rest in of a stack with 5000 nanocapacitors. We show that during the deceleration process more than 90% of kinetic energy of charged nuclear reaction products is converted to electric energy and stored as electric energy in the stack. Each stack is 2.5‐mm thick and produces a high‐voltage DC current. A device with a 1‐Ci241Am source is expected to generate 22 mW of electric power. 相似文献
89.
Dave Anderson Mathieu Florence Zinovy Reichstein 《Comptes Rendus Mathematique》2013,351(23-24):871-875
Let G be a split simple group of type over a field k, and let be its Lie algebra. Answering a question of J.-L. Colliot-Thélène, B. Kunyavski?, V.L. Popov, and Z. Reichstein, we show that the function field is generated by algebraically independent elements over the field of adjoint invariants . 相似文献
90.
John Wood Ahmet Tekin Adrian Dave Kenneth Pedrotti 《Analog Integrated Circuits and Signal Processing》2008,55(2):139-148
In this paper, an 8-bit 1.2 Gsample/s single-slope ADC architecture is presented. The proposed technique utilizes the picosecond-accurate phases of a rotary traveling wave oscillator (RTWO). The proof-of-concept test chip is fabricated in a 0.18-μm CMOS process and occupies 1.3 mm × 1.3 mm of die area. Power consumption is 36 mW for the core and 135 mW for on-chip clocks. 相似文献