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61.
C. K. Nisha Sunkara V. Manorama Souvik Maiti K. N. Jayachandran V. K. Aswald P. S. Goyal 《Pramana》2004,63(2):315-320
The interaction of cationic random copolymers of methoxy poly(ethylene glycol) monomethacrylate and (3-(methacryloylamino)propyl) trimethylammonium chloride with oppositely charged surfactant, sodium dodecyl sulphate, and the influence of surfactant association on the polymer conformation have been investigated by small-angle neutron scattering. SANS data showed a positive indication of the formation of RCPSDS complexes. Even though the complete structure of the polyion complexes could not be ascertained, the results obtained give us the information on the local structure in these polymer-surfactant systems. The data were analysed using the log-normal distribution of the polydispersed spherical aggregate model for the local structure in these complexes. For all the systems the median radius and the polydispersity were found to be in the range of 20 ± 2 Å and 0.6 ± 0.05, respectively. 相似文献
62.
Multi-item inventory models with stock dependent demand and two storage facilities are developed in a fuzzy environment where processing time of each unit is fuzzy and the processing time of a lot is correlated with its size. These are order-quantity reorder-point models with back-ordering if required. Here possibility and crisp constraints on investment and capacity of the small storehouse respectively are considered. The models are formulated as fuzzy chance constrained programming problem and is solved via generalized reduced gradient (GRG) technique when crisp equivalent of the constraints are available. A genetic algorithm (GA) is developed based on fuzzy simulation and entropy where region of search space gradually decreases to a small neighborhood of the optima and it is used to solve the models whenever the equivalent crisp form of the constraint is not available. The models are illustrated with some numerical examples and some sensitivity analyses have been done. For some particular cases results observed via GRG and GA are compared. 相似文献
63.
Palladium(II)‐Catalyzed meta‐CH Olefination: Constructing Multisubstituted Arenes through Homo‐Diolefination and Sequential Hetero‐Diolefination 下载免费PDF全文
Dr. Milan Bera Arun Maji Dr. Santosh K. Sahoo Prof. Debabrata Maiti 《Angewandte Chemie (International ed. in English)》2015,54(29):8515-8519
Divinylbenzene derivatives represent an important class of molecular building blocks in organic chemistry and materials science. Reported herein is the palladium‐catalyzed synthesis of divinylbenzenes by meta‐C? H olefination of sulfone‐based arenes. Successful sequential olefinations in a position‐selective manner provided a novel route for the synthesis of hetero‐dialkenylated products, which are difficult to access using conventional methods. Additionally, 1,3,5‐trialkenylated compounds can be generated upon successful removal of the directing group. 相似文献
64.
Sanchita Mondal Saikat Kumar Manna Kalipada Maiti Rajkishor Maji Syed Samim Ali Srimanta Manna 《Supramolecular chemistry》2017,29(8):616-626
A FRET-based chemosensor L containing donor phenanthroline and acceptor fluorescein moiety was designed, synthesised and characterised for the ratiometric fluorescent detection of Cu2+ in organo-aqueous solution. Probe L showed high selectivity and excellent sensitivity towards Cu2+ ions by exhibiting both colorimetric and fluorometric changes due to opening of the spirolactum ring of fluorescein upon complexation with Cu2+. In presence of Cu2+ ions, probe L formed L-Cu2+ complex in 1:1 stoichiometric fashion which is established on the basis of Job’s plot and mass spectroscopy. We also performed DFT computational studies to know the binding nature and coordination feature of the complex. Furthermore, fluorescence imaging studies revealed that probe L was cell permeable and could be used to detect intracellular Cu2+ in living cells. 相似文献
65.
Amitesh Maiti 《International journal of quantum chemistry》2014,114(3):163-175
With the negative environmental implications of the anthropogenic emission of greenhouse gases like CO2 having been scientifically established, emphasis is being placed on a concerted global effort to prevent such gases from reaching the atmosphere. Especially important are capture efforts at large point emission sources like fossil fuel power generation, natural gas processing, and various industrial plants. Given the importance and scale of such activities, it is a significant priority to optimize the capture process in terms of speed, energy requirements, and cost efficiency. For CO2 capture, in particular, multiple systems are being pursued both with near‐term retrofitting and medium‐ to long‐term designs in mind, including: (1) liquid solvents like amines, carbonates, and ionic liquids (ILs); (2) microporous sorbents like zeolites, activated carbon, and metal‐organic frameworks; (3) solid sorbents like metal‐oxides and ionic clays; and (4) polymeric and inorganic membrane separators. Each system is unique in its molecular‐level guest–host interactions, chemistry, heats of adsorption/desorption, and equilibrium thermodynamic and transport properties as a function of loading, temperature, and pressure. This opens up exciting opportunities for molecular modeling in the design and optimization of materials systems. Here, we offer a brief survey of molecular modeling applications in the field of carbon capture, with a few illustrative examples from our own work primarily involving amine solutions and ILs. Important molecular dynamics, Monte Carlo, and correlations‐based work in the literature relevant to CO2 capture in other systems are also discussed. © 2013 Wiley Periodicals, Inc. 相似文献
66.
Kumar H Mukherjee B Lin ST Dasgupta C Sood AK Maiti PK 《The Journal of chemical physics》2011,134(12):124105
Experiments and computer simulations demonstrate that water spontaneously fills the hydrophobic cavity of a carbon nanotube. To gain a quantitative thermodynamic understanding of this phenomenon, we use the recently developed two phase thermodynamics method to compute translational and rotational entropies of confined water molecules inside single-walled carbon nanotubes and show that the increase in energy of a water molecule inside the nanotube is compensated by the gain in its rotational entropy. The confined water is in equilibrium with the bulk water and the Helmholtz free energy per water molecule of confined water is the same as that in the bulk within the accuracy of the simulation results. A comparison of translational and rotational spectra of water molecules confined in carbon nanotubes with that of bulk water shows significant shifts in the positions of the spectral peaks that are directly related to the tube radius. 相似文献
67.
Nagarwal RC Singh PN Kant S Maiti P Pandit JK 《Chemical & pharmaceutical bulletin》2011,59(2):272-278
The aim of this investigation was to develop 5-fluorouracil (5-FU) loaded chitosan nanoparticles (CH-DNPs) for ophthalmic delivery. CH-DNPs were fabricated by ionotropic gelation mechanism using chitosan (CH) and a polyanion (TPP). The nanoparticles were smooth and spherical, confirmed by scanning electron microscopy (SEM) and atomic force microscope (AFM). CH/TPP mass ratio and TPP significantly changed the particles size morphology and encapsulation efficiency. The nanoparticles size ranged from approximately 114 to 192 nm and had a positive zeta potential (30±4 mV). The encapsulation efficiency, loading capacity and recovery of DNPs were 8.12-34.32%, 3.14-15.24% and 24.22 to 67% respectively. Physical characterization was done by Fourier transform infrared (FT-IR) and X-ray diffraction (XRD). No interaction was observed in between drug and polymer and crystallinity of drug was not changed in drug loaded nanoparticles. In-vitro release study of DNPs showed diffusion controlled release. Bioavailability study of batch CS9 was studied in rabbit eye and compare to 5-FU solution. 5-FU level was significantly higher in aqueous humor of rabbit eye. Ocular tolerance was studied in the eye of New Zealand rabbits and tested formulation was non-irritant with no sign of inflammation. 相似文献
68.
Maiti KK Samanta A Vendrell M Soh KS Olivo M Chang YT 《Chemical communications (Cambridge, England)》2011,47(12):3514-3516
SERS nanotags have been prepared to accomplish the multiplex detection of cancer cells. Herein we evaluated the adequacy of lipoic acid-containing cyanine derivatives (Cy3LA and Cy5LA) to function as multiplex partners with a triphenylmethine Raman reporter (B2LA) under a single excitation wavelength. SERS experiments enabled the multiplex recognition of two different cancer cells with antibody-conjugated nanotags that were derivatized with optimized cyanine and triphenylmethine reporters. 相似文献
69.
Maiti D 《Chemical communications (Cambridge, England)》2011,47(29):8340-8342
An orthogonal set of Cu-catalysts for the selective mono-arylation of alkyl aryl diols using aryl iodides is presented. Picolinic acid ligated copper catalyst provided phenol O-arylation only, while alkyl aryl ethers are generated by ligand-free copper catalyst in the presence of 2 equivalents NaOt-Bu. 相似文献
70.
Oil-water interface in the two-dimensional Larson type of model 总被引:2,自引:0,他引:2
Prabal K. Maiti 《Physics letters. A》1997,230(5-6):369-372