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排序方式: 共有593条查询结果,搜索用时 15 毫秒
91.
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93.
Martino L Virno A Pagano B Virgilio A Di Micco S Galeone A Giancola C Bifulco G Mayol L Randazzo A 《Journal of the American Chemical Society》2007,129(51):16048-16056
The complex between distamycin A and the parallel DNA quadruplex [d(TGGGGT)]4 has been studied by 1H NMR spectroscopy and isothermal titration calorimetry (ITC). To unambiguously assert that distamycin A interacts with the grooves of the quadruplex [d(TGGGGT)]4, we have analyzed the NMR titration profile of a modified quadruplex, namely [d(TGGMeGGT)]4, and we have applied the recently developed differential frequency-saturation transfer difference (DF-STD) method, for assessing the ligand-DNA binding mode. The three-dimensional structure of the 4:1 distamycin A/[d(TGGGGT)]4 complex has been determined by an in-depth NMR study followed by dynamics and mechanics calculations. All results unequivocally indicate that distamycin molecules interact with [d(TGGGGT)]4 in a 4:1 binding mode, with two antiparallel distamycin dimers that bind simultaneously two opposite grooves of the quadruplex. The affinity between distamycin A and [d(TGGGGT)]4 enhances ( approximately 10-fold) when the ratio of distamycin A to the quadruplex is increased. In this paper we report the first three-dimensional structure of a groove-binder molecule complexed to a DNA quadruplex structure. 相似文献
94.
Summary The dielectric and electronic properties of thianthren (C6H4(S)2H4C6) are determined by means of optical reflectivity, absorption measurements and reflection electron energy loss spectroscopy.
The experimental results are interpreted on the basis of a Complete Neglect of Differential Overlap (CNDO) calculation used
in three different parametrization schemes. Emphasis is laid on the discussion of the problems which generally affect the
analysis of electron energy loss spectra, and a procedure to obtain the complex dielectric function from electron energy loss
measurements performed in the reflection mode is suggested.
Work partially supported by the MURST through the GNSM. 相似文献
95.
C. Camerlingo H. Huang B. Ruggiero M. Russo E. Sarnelli G. Testa 《Il Nuovo Cimento D》1994,16(12):1967-1972
Summary Bicrystal grain boundary junctions of YBCO have been fabricated by using the Inverted Cylindrical Magnetron d.c. sputtering
technique. The main characteristics of the junction behaviour are reported. Some aspects of the experimental results are discussed
in the framework of existing models developed for describing weak-link structures.
Paper presented at the ?VII Congresso SATT?, Torino, 4–7 October 1994. 相似文献
96.
Summary The structural and electronic characterization of thieno [3,4-b][1,4]-diazepine and 1,5-benzodiazepine systems was carried
out by semi-empirical quantum-mechanical calculations. A number of electronic properties were computed and examined in order
to study the structure-activity relationship. Theoretical data indicate that the electronic rather than structural properties
appear primarily responsible for the variant degree of anticonvulsant activity exhibited by compounds 1–4. 相似文献
97.
Martino Bardi 《Journal of Differential Equations》1985,58(3):364-380
The method of moving parallel planes, previously used for elliptic and parabolic PDE, is adapted to study solutions of the Cauchy problem for Hamilton-Jacobi equations. This is possible in the framework of the theory of viscosity solutions, using the comparison theorem for such solutions as a kind of maximum principle. One of the main results states that if the initial data are nonnegative and compact supported, the Hamiltonian radial and the level sets expanding, then the level sets become asymptotically spherical as t → ∞, the convergence taking place in the Lipschitz norm. 相似文献
98.
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100.
P. Mison R. Chaabouni Y. Diab R. Martino A. Lopez A. Lattes F. W. Wehrli T. Wirthlin 《Magnetic resonance in chemistry : MRC》1976,8(2):79-89
13C chemical shifts for twenty-nine alkyl and phenyl substituted N-unsubstituted aziridines have been measured. Additivity parameters for methyl, phenyl and aziridyl carbons have been derived with the aim of testing the consistency of the assignments made on the basis of chemical shift considerations and off-resonance decoupling information. The observed chemical shifts are discussed in terms of steric and pseudoconjugation effects. 相似文献