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61.
Neeraj K. Jaiswal Pankaj Srivastava 《Physica E: Low-dimensional Systems and Nanostructures》2011,44(1):75-79
We have investigated the electronic properties of bare, H-terminated, Cu-terminated and Cu-doped armchair graphene nanoribbons (AGNRs) using ab-initio approach. We found that H-termination enhances the stability and band gap whereas H extraction introduces dangling bands and lowers the band gap making bare ribbons indirect band gap semiconductors. The calculations revealed that strong hybridization between Cu atoms and AGNRs, lessen the band gap for Cu-terminated ribbons and gives rise to metallicity in Cu-doped AGNRs irrespective of their widths. Formation energy of considered ribbons yield that H-terminated AGNRs with lowest formation energy are most energetically favored, next are one edge Cu-terminated ribbons followed by bare ones whereas both edges Cu-doped ribbons are least energetically plausible. We predict that presence of Cu atoms in GNRs, significantly alter the band gap and can be used in band gap engineering of nanoribbons. 相似文献
62.
Mahesh Kumar Thirumaleshwara N. Bhat Mohana K. Rajpalke Basanta Roul Neeraj Sinha A.T. Kalghatgi S.B. Krupanidhi 《Surface science》2011,605(15-16):L33-L37
InN layers were directly grown on Ge substrate by plasma-assisted molecular beam epitaxy (PAMBE). The valence band offset (VBO) of wurtzite InN/Ge heterojunction is determined by X-ray photoemission spectroscopy (XPS). The valence band of Ge is found to be 0.18 ± 0.04 eV above that of InN and a type-II heterojunction with a conduction band offset (CBO) of ~ 0.16 eV is found. The accurate determination of the VBO and CBO is important for the design of InN/Ge based electronic devices. 相似文献
63.
S. K. Mohanta S. N. Mishra S. M. Davane Neeraj Kumar A. Thamizhavel S. Layek Z. Hossain S. K. Srivastava 《Hyperfine Interactions》2013,221(1-3):23-27
Employing the γ-ray perturbed angular distribution technique, we have measured the magnetic hyperfine field of 54Fe in tetragonal and orthorhombic structural phases of SrFe2As2. In the tetragonal phase, the magnetic response of 54Fe shows Curie-Weiss type local susceptibility, indicating the presence of localized moment on Fe. The temperature dependence of the hyperfine field of 54Fe reflects quasi-two dimensional first order magnetic transition at 200 K. Our data indicate that Fe moments in the magnetically ordered phase of SrFe2As2 may be canted out of the ab-plane. 相似文献
64.
Mahesh Kumar Basanta Roul Thirumaleshwara N. Bhat Mohana K. Rajpalke Neeraj Sinha A. T. Kalghatgi S. B. Krupanidhi 《Journal of nanoparticle research》2011,13(3):1281-1287
One of the scientific challenges of growing InN quantum dots (QDs), using Molecular beam epitaxy (MBE), is to understand the
fundamental processes that control the morphology and distribution of QDs. A systematic manipulation of the morphology, optical
emission, and structural properties of InN/Si (111) QDs is demonstrated by changing the growth kinetics parameters such as
flux rate and growth time. Due to the large lattice mismatch, between InN and Si (~8%), the dots formed from the Strannski–Krastanow
(S–K) growth mode are dislocated. Despite the variations in strain (residual) and the shape, both the dot size and pair separation
distribution show the scaling behavior. We observed that the distribution of dot sizes, for samples grown under varying conditions,
follow the scaling function. 相似文献
65.
Abstract Recently very encouraging results of semiempirical parameteric calculation of dipole transition moments of the lowest energy t1 ? 2e (1A1 - 1T2) transition of permanganate and chromate ions have been reported. In the case of vanadate ion, which is isoelectronic with the permanganate and chromate ion, no such study of spectral intensities appears to have been reported so far. A parameteric calculation in terms of a single parameter β, the ligand mixing coefficient using Richardson's orbitals4 and both dipole velocity and dipole length operators have been reported in the present paper. 相似文献
66.
A simple and efficient methodology for Markovnikov addition of azoles with vinyl acetate catalyzed by potassium tert-butoxide is described.N-heterocyclic compounds are synthesized from simple and commercially available starting materials under mild conditions in high yields. 相似文献
67.
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69.
Runjhun Tandon Vijay Luxami Harsovin Kaur Nitin Tandon Kamaldeep Paul 《Chemical record (New York, N.Y.)》2017,17(10):956-993
The poor pharmacokinetics, side effects and particularly the rapid emergence of drug resistance compromise the efficiency of clinically used anticancer drugs. Therefore, the discovery of novel and effective drugs is still an extremely primary mission. Naphthalimide family is one of the highly active anticancer drug based upon effective intercalator with DNA. In this article, we review the discovery and development of 1,8‐naphthalimide moiety, and, especially, pay much attention to the structural modifications and structure activity relationships. The review demonstrates how modulation of the moiety affecting naphthalimide compound for DNA binding that is achieved to afford a profile of antitumor activity. The DNA binding of imide and ring substitution at naphthalimide, bisnaphthalimide, naphthalimide‐metal complexes is achieved by molecular recognition through intercalation mode. Thus, this synthetic/natural small molecule can act as a drug when activation or inhibition of DNA function, is required to cure or control the cancer disease. The present study is a review of the advances in 1,8‐naphthalimide‐related research, with a focus on how such derivatives are intercalated into DNA for their anticancer activities. 相似文献
70.
Ambrish Kumar Srivastava Neeraj Misra 《International journal of quantum chemistry》2014,114(5):328-332
Density functional calculations on the ground state geometries and stabilities of PdOn species (n = 1–5) are performed in neutral as well as anionic forms. Calculations reveal that Pd can bind stably with four O atoms indicating the maximum oxidation state of Pd as high as +8. The electron affinities of PdOn suggest that these species behave as superhalogens for n ≥ 2. The large electron affinities of PdOn species along with stability of their anions point toward the synthesis of new class of compounds having unusual oxidizing capabilities. This possibility is explored by considering the interaction of PdO2 superhalogen with Ca atom which forms a stable CaPdO2 complex. In this complex, PdO2 unit closely mimics the behavior of O atom when compared with CaO molecule. © 2013 Wiley Periodicals, Inc. 相似文献