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41.
In this Letter we have studied a new form of non-commutative (NC) phase space with an operatorial form of noncommutativity. A point particle in this space feels the effect of an interaction with an “internal ” magnetic field, that is singular at a specific position θ−1. By “internal” we mean that the effective magnetic fields depends essentially on the particle properties and modifies the symplectic structure. Here θ is the NC parameter and induces the coupling between the particle and the “internal” magnetic field. The magnetic moment of the particle is computed. Interaction with an external physical magnetic field reveals interesting features induced by the inherent fuzziness of the NC phase space: introduction of non-trivial structures into the charge and mass of the particle and possibility of the particle dynamics collapsing to a Hall type of motion. The dynamics is studied both from Lagrangian and symplectic (Hamiltonian) points of view. The canonical (Darboux) variables are also identified. We briefly comment, that the model presented here, can play interesting role in the context of (recently observed) real space Berry curvature in material systems. 相似文献
42.
Srinivasa Rao Karumuri Joydeep Choudhury Nirmal Kumar Sarkar Ramendu Bhattacharjee 《Pramana》2010,74(1):57-66
Using Lie algebraic techniques and simpler expressions of the matrix elements of Majorana and Casimir operators given by us,
we obtain an effective Hamiltonian operator which conveniently describes stretching vibrations of biomolecules. For a copper
tetramesityl porphyrin molecule, the higher excited vibrational levels are calculated by applying the U(2) algebraic approach. 相似文献
43.
Plaban Jyoti Sarma Debojyoti Bhattacharjee Bhupesh Kumar Mishra 《Molecular physics》2017,115(8):962-970
Dual level of quantum mechanical calculations have been carried out for hydrogen abstraction from Piperazine [HN(CH2CH2)2NH] initiated by OH radical. Geometry optimisation and frequency calculations of all species involved in the titled reaction have been performed at M06-2X/6-31+G(d,p) level of theory. For the accuracy in the thermochemistry and kinetics data, single-point energy calculations have been further carried out at coupled cluster CCSD(T) method along with 6-311G(d,p) basis set. An energy profile diagram for the reaction has been plotted along with pre-reactive and post-reactive complexes at entrance and exit channels. Intrinsic reaction coordinates (IRCs) calculations have been performed for identification of real transition states that connect it via reactant to product. Our result shows that the H-atom abstraction takes place from the C–H position of Piperazine. The rate constant is calculated using canonical transition state theory (CTST) is found to be 2.86 × 10?10 cm3 molecule?1 s?1 which is in good agreement with the reported experimental rate constant (2.38 ± 0.28) × 10?10 cm3 molecule?1 s?1 at 298 K. We have also reported rate constant for the temperature range 300–500 K. Using group-balance isodesmic reaction, the standard enthalpies of formation for Piperazine and product radicals generated by hydrogen abstraction are reported. The branching ratios for both reaction channel (i.e. H-abstraction from –CH2 and –NH position of Piperazine) are found to be 93% and 7%, respectively. The calculated atmospheric life time of Piperazine is found to be 0.97 hour. 相似文献
44.
Self-assembling behaviour of block copolymers and their ability to evade the immune system through polyethylene oxide stealth
makes it an attractive candidate for drug encapsulation. Micelles formed by polyethylene oxide-polypropylene oxide- polyethylene
oxide triblock copolymers (PEO-PPO-PEO), pluronic P123, have been employed for encapsulating the anti-cancer drug doxorubicin
hydrochloride. The binding affinity of doxorubicin within the micelle carrier is enhanced through complex formation of drug
and anionic surfactant, aerosol OT (AOT). Electrostatic binding of doxorubicin with negatively charged surfactants leads to
the formation of hydrophobic drug-surfactant complexes. Surfactant-induced partitioning of the anti-cancer drug into nonpolar
solvents such as chloroform is investigated. SANS measurements were performed on pluronic P123 micelles in the presence of
drug-surfactant complex. No significant changes in the structure of the micelles are observed upon drug encapsulation. This
demonstrates that surfactant- drug complexes can be encapsulated in block copolymer micelles without disrupting the structure
of aggregates.
相似文献
45.
We employ a layer-by-layer adsorption technique for deposition on solid substrates of polyionic films of Chicago Sky Blue. Film growth was significant with the increasing number of layers. Photochemical properties of these films are investigated for different ionic concentrations. A significant blue shift is observed with the increasing ionic strength of the solution, suggesting the formation of aggregation. Temperature effect studies show some preferable reorientation of molecules in the film during cooling process. Most remarkable observation is that the absorption intensity is the highest for a particular degree of inclination. Deposition time is fixed at 15rain because adsorption kinetics results show saturation after 15 min. 相似文献
46.
P. C. Deka H. Sarma Subir Sarkar T. D. Goswami B. K. Sarma 《Indian Journal of Physics》2009,83(7):1025-1030
With the growing understanding of the role of radon and its daughter products as major sources of radiation exposure, the
importance of large number of estimation of radon concentration in various parts of the country is realized. Inhalation of
radon, thoron and their decay products is the major source of the total radioactive dose received by the human population
from natural radiation. The indoor radon and thoron progeny levels in Nalbari area of Assam are studied by using the LR-115
(type II) Solid State Nuclear Track Detector in Plastic Twin Chamber dosimeter. Radon and thoron progeny levels in different
types of dwellings for one full calendar year are presented in this paper. For Assam Type (A.T.) houses, indoor radon progeny
concentrations vary from 0.17 to 0.64 mWL with an annual geometric mean of 0.27 mWL and that for Reinforced Cement Concrete
(R.C.C.) houses vary from 0.22 mWL to 0.60 mWL with the annual geometric mean of 0.37 mWL. The thoron progeny levels in A.T.
houses also vary from 0.01 to of 0.05 mWL with an annual geometric mean of 0.02 mWL and that for R.C.C. houses vary from 0.02
to 0.08 mWL with the annual geometric mean of 0.04 mWL.
相似文献
47.
Debanjan Bhattacharjee Parameswara Rao Alapati 《Molecular Crystals and Liquid Crystals》2017,648(1):66-76
This article represents the electrical studies of an interdigitated highly skewed N(4-n-pentyloxybenzylidene) 4-n-alkylaniline (5O.16) compound. Interestingly the compound is partially bent like and unsymmetrical in alkyl chain length. Dielectric and impedance spectroscopy studies indicate the coupling between the liquid crystal and the electrical field. Studies were carried out as a function of temperature as well as frequency. Semicircular nature of the Cole–Cole plots indicates the reorientation of the molecule with the applied field. Using the experimental data and the theoretically fitted results the effective equivalent model circuit was designed. Which used to explain the behavior of the compound under the external electric effect and the influence of the electrodes with different variable represent the resistor circuit. However, the effect of the conductivity of temperature and frequency are also reported. 相似文献
48.
We consider the Sel’kov model of glycolytic oscillator for a quantitative study of the limit cycle oscillations in the system.
We identify a region of parameter space where perturbation theory holds and use both Linstedt Poincaré technique and harmonic
balance to obtain the shape and frequency of the limit cycle. The agreement with the numerically obtained result is excellent.
We also find a different extreme, where the limit cycle is of the relaxation oscillator variety, has a large time period and
it is seen that, as a particular parameter in the model is varied, the time period increases indefinitely. We characterize
this divergence numerically. A calculational method is devised to capture the divergence approximately. 相似文献
49.
A. Bhattacharyay J.K. Bhattacharjee 《The European Physical Journal B - Condensed Matter and Complex Systems》1999,8(1):137-141
Reaction diffusion systems can exhibite both spatial and temporal patterns. We show that the effect of spatial variation of
the removal rate can have significant effect on the stability boundaries. In particular there can be a case of parametric
resonance.
Received 11 March 1998 相似文献
50.
Dey Chaudhuri S. Banerjee D. Bhattacharjee T. Wasim Raja Sk Acharya R. Pujari P. K. 《Journal of Radioanalytical and Nuclear Chemistry》2020,324(2):829-835
Journal of Radioanalytical and Nuclear Chemistry - Performance of 1″?×?1″ LaBr3 (5% Ce) scintillator coupled to Hamamatsu R2083 PM Tube has been investigated for the... 相似文献