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991.
S. K. Datta Lalit Kumar B. N. Basu 《International Journal of Infrared and Millimeter Waves》2008,29(6):608-616
An accurate and simple closed-form formula, for backward-wave start-oscillation condition for a millimeter-wave helix traveling-wave
tube amplifier was developed, using an artificial neural network (ANN) algorithm. The analysis considers the effects of circuit
loss and also the variation of electron beam diameter corresponding to beam filling. The formula is simple and amenable to
easy computation, even using a scientific calculator, and without resorting to exhaustive numerical iterative search followed
in conventional analyses and, at the same time, without sacrificing the accuracy in results. The formula was validated against
published results, and excellent accuracy was observed. The analysis has been further used for inferring some physical interpretations
on the effects of beam-filling factor and circuit loss on the start-oscillation condition of a typical millimeter-wave helix
traveling-wave tube. 相似文献
992.
BARC is developing a technology for the accelerator-driven subcritical system (ADSS) that will be mainly utilized for the
transmutation of nuclear waste and enrichment of U233. Design and development of superconducting medium velocity cavity has been taken up as a part of the accelerator-driven subcritical
system project. We have studied RF properties of 700 MHz, β = 0.42 single cell elliptical cavity for possible use in high current proton acceleration. The cavity shape optimization
studies have been done using SUPERFISH code. A calculation has been done to find out the velocity range over which this cavity
can accelerate protons efficiently and to select the number of cells/cavity. The cavity’s peak electric and magnetic fields,
power dissipation P
c
, quality factor Q and effective shunt impedance ZT
2 were calculated for various cavity dimensions using these codes. Based on these analyses a list of design parameters for
the inner cell of the cavity has been suggested for possible use in high current proton accelerator.
相似文献
993.
Quantum discord and the power of one qubit 总被引:1,自引:0,他引:1
We use quantum discord to characterize the correlations present in the model called deterministic quantum computation with one quantum bit (DQC1), introduced by Knill and Laflamme [Phys. Rev. Lett. 81, 5672 (1998)10.1103/PhysRevLett.81.5672]. The model involves a collection of qubits in the completely mixed state coupled to a single control qubit that has nonzero purity. The initial state, operations, and measurements in the model all point to a natural bipartite split between the control qubit and the mixed ones. Although there is no entanglement between these two parts, we show that the quantum discord across this split is nonzero for typical instances of the DQC1 ciruit. Nonzero values of discord indicate the presence of nonclassical correlations. We propose quantum discord as figure of merit for characterizing the resources present in this computational model. 相似文献
994.
MVN Murthy Urjit A Yajnik KRS Balaji G Bhattacharyya Amol Dighe Shashikant Dugad ND Hari Dass PK Kabir Kamales Kar D Indumathi John G Learned Debasish Majumdar NK Mondal MVN Murthy SN Nayak Sandip Pakvasa Amitava Raychaudhuri RS Raghavan G Rajasekaran R Ramachandran Alak K Ray Asim K Ray Saurabh Rindani HS Sharatchandra Rahul Sinha Nita Sinha S Umasankar Urjit A Yajnik 《Pramana》2000,55(1-2):347-355
We have identified some important and worthwhile physics opportunities with a possible neutrino detector located in India.
Particular emphasis is placed on the geographical advantage with a stress on the complimentary aspects with respect to other
neutrino detectors already in operation. 相似文献
995.
996.
U Datta Pramanik T Aumann D Cortina H Emling H Geissel M Hellström R Holzmann N Iwasa Y Leifels G Münzenberg M Rejmund C Scheidenberger K Sümmerer A Leistenschneider Th W Elze A Grünschloss S Ilievski K Boretzky J V Kratz R Kulessa E Lubkiewicz E Wajda W Walus P Reiter H Simon 《Pramana》2001,57(2-3):535-544
Coulomb breakup of neutron-rich nuclei around mass A ∼ 20 has been studied experimentally using secondary beams (∼ 500–600 MeV/u) of unstable nuclei produced at GSI. The spectroscopic
factor deduced for the neutron occupying s
1/2 level in 15C ground state is consistent with the earlier reported value. The data analysis for Coulomb breakup of 17C shows that most of the cross section yields the 16C core in its excited state. For 17–22O, the low-lying E1 strength amounts up to about 12% of the energy weighted dipole sum rule strength depending on neutron
excess. The cluster sum rule limit with 16O as a core is almost exhausted for 17,18O, while for more neutron rich isotopes the strength with respect to that limit decreases. 相似文献
997.
In modern day scenario, biosorption is a cost effective separation technology for the removal of various pollutants from wastewater
and waste streams from various process industries. The difficulties associated in rigorous mathematical modeling of a fixed
bed bio-adsorbing systems due to the complexities of the process often makes the development of pure black-box artificial
neural network (ANN) models particularly useful in this field. In this work, radial basis function network has been employed
as ANN to model the breakthrough curves in fixed bed biosorption. The prediction has been compared to the experimental breakthrough
curves of Cadmium, Lanthanum and a dye available in the literature. Results show that this network gives fairly accurate representation
of the actual breakthrough curves. The results obtained from ANN modeling approach shows the better agreement between experimental
and predicted breakthrough curves as the error for all these situations are within 6%. 相似文献
998.
Somnath Datta Glen A. Satten John M. Williamson 《Annals of the Institute of Statistical Mathematics》2000,52(1):160-172
Satten et al. (1998, J. Amer. Statist. Assoc., 93, 318–327) proposed an approach to the proportional hazards model for interval censored data in which parameter estimates are obtained by solving estimating equations which are the score equations for the full data proportional hazards model, averaged over all rankings of imputed failure times consistent with the observed censoring intervals. In this paper, we extend this approach to incorporate data that are left-truncated and right censored (dynamic cohort data). Consistency and asymptotic normality of the estimators obtained in this way are established. 相似文献
999.
Ming-Tzu Ho Aniruddha Datta S. P. Bhattacharyya 《Linear algebra and its applications》2000,320(1-3):23-36
The Hermite–Biehler theorem gives necessary and sufficient conditions for the Hurwitz stability of a polynomial in terms of certain interlacing conditions. In this paper, we extend our earlier generalization of the Hermite–Biehler theorem for real, not necessarily Hurwitz polynomials to the domain of polynomials with complex coefficients. This result, which is of interest in its own right, can also be used to analytically solve an important stabilization problem in control theory. 相似文献
1000.
In this paper we report on the treatment of industrial fibers and cords by means of plasma polymerization techniques. Coatings of plasma-polymerized pyrrole or acetylene were deposited on aramid fibers, aramid cords and polyester cords. The equipment was a custom-built semi-continuous reactor operated on a pulsed DC glow discharge. The fibers and cords were tested for adhesion to various polymers such as tire cord skim stock rubber compounds and epoxy adhesives. Standard industrial pull-out force adhesion measurement techniques were used. The deposition conditions of the plasma polymer films were varied within wide limits. It was found that, in general, films deposited under low-power and high-pressure conditions performed better than films prepared under high-power and low-pressure conditions. For some systems pulsing of the discharge power improved the performance further. For all systems studied, the optimized plasma polymer surface modification outperformed current industrial standards. The plasma-polymerized coatings were characterized by various techniques and the excellent performance results are explained in a tentative model based on the molecular structure of the films. This structure was found to be strongly dependent on the discharge conditions. 相似文献