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排序方式: 共有194条查询结果,搜索用时 15 毫秒
71.
D. Patel S. Mukherjee N. Deshmukh J. Lubian Jian-Song Wang T. Correa B. K. Nayak Yan-Yun Yang Wei-Hu Ma D. C. Biswas Y. K. Gupta S. Santra E. T. Mirgule L. S. Danu N. L. Singh A. Saxena 《中国物理C(英文版)》2017,41(10):104001-104001
The effects of breakup reactions on elastic and α-production channels for the ~6Li+~(116)Sn system have been investigated at energies below and near the Coulomb barrier. The angular distributions of α-particle production differential cross sections have been obtained at several projectile energies between 22 and 40 MeV. The measured breakup α-particle differential cross sections and elastic scattering angular distributions have been compared with the predictions of continuum-discretized coupled channels(CDCC) calculations. The influence of breakup coupling has also been investigated by extracting dynamic polarization potentials(DPP) from the CDCC calculations. From the predictions of CDCC calculations the relative importance of the nuclear, Coulomb, and total breakup contributions have also been investigated. The nuclear breakup couplings are observed to play an important role in comparison to the Coulomb breakup for the direct breakup mechanisms associated in the reaction of ~6Li projectile with ~(116)Sn target nuclei. The influence of strong nuclear breakup coupling exhibits suppression in the Coulomb-nuclear interference peak. The direct breakup cross sections from the CDCC calculations under-predict the measured α-particle differential cross sections at all energies. This suggests that the measured α particles may also have contributions from other possible breakup reaction channels. 相似文献
72.
Nataliya V. Slovesnova Artem S. Minin Anna V. Belousova Aleksey A. Ustyugov Kirill D. Chaprov Alexey P. Krinochkin Maria I. Valieva Yaroslav K. Shtaitz Ekaterina S. Starnovskaya Igor L. Nikonov Anton N. Tsmokalyuk Grigory A. Kim Sougata Santra Dmitry S. Kopchuk Emiliya V. Nosova Grigory V. Zyryanov 《Molecules (Basel, Switzerland)》2022,27(23)
Linked to Alzheimer’s disease (AD), amyloids and tau-protein are known to contain a large number of cysteine (Cys) residues. In addition, certain levels of some common biogenic thiols (cysteine (Cys), homocysteine (Hcy), glutathione (GSH), etc.) in biological fluids are closely related to AD as well as other diseases. Therefore, probes with a selective interaction with the above-mentioned thiols can be used for the monitoring and visualizing changes of (bio)thiols in the biological fluids as well as in the brain of animal models of Alzheimer’s disease. In this study, new Eu(III), Tb(III), Gd(III) and Sm(III) complexes of 2,2′-bipyridine ligands containing TEMPO fragments as receptor units for (bio)thiols are reported. The presence of free radical fragments of the ligand in the complexes was proved by using the electronic paramagnetic resonance (EPR) method. Among all the complexes, the Eu(III) complex turned out to be the most promising one as luminescence- and spin-probe for the detection of biogenic thiols. The EPR and fluorescent titration methods showed the interaction of the resulting complex with free Cys and GSH in solution. To study the practical applicability of the probes for the monitoring of AD in-vivo, by using the above-mentioned Eu(III)-based probe, the staining of the brain of mice with amyloidosis and Vero cell cultures supplemented with the cysteine-enriched medium was studied as well as the fluorescence titration of Bovine Serum Albumin, BSA (as the model for the thiol moieties containing protein), was carried out. Based on the results of fluorescence titration, the formation of a non-covalent inclusion complex between the above-mentioned Eu(III) complex and BSA was suggested. 相似文献
73.
Sachin B. Baravkar Mahendra A. Wagh Debasish Paul Manas Santra Gangadhar J. Sanjayan 《Tetrahedron letters》2018,59(38):3473-3476
Herein, we report synthesis and in vitro anticancer activity of conformationally constrained Smac mimetics containing reverse turn inducing motifs “Ant-Pro” and “sAnt-Pro”. The synthesis of Smac analogs with diverse hydrophobic groups at the C-terminus was carried out using solution phase peptide synthesis. The synthesis of Ant-Pro containing analogs 3a–j was carried out by ring opening of benzoxazinones 7a–c, whereas, their sulfonamide counterparts 4a–h were synthesized by using routine acid-amine coupling reaction. In vitro anticancer studies against breast cancer cell line MDA-MB-231 revealed that some of the new analogs had better anticancer activity than the standard AVPI Smac tetrapeptide. 相似文献
74.
The beam optics of the 6 MV folded tandem ion accelerator, that has recently been commissioned at Bhabha Atomic Research Centre,
Mumbai, is presented. Typical beam trajectories for proton and 12C beams under different conditions, are shown. The constraints on the design due to the use of the infrastructure of the Van
de Graaff accelerator, which existed earlier, are discussed. 相似文献
75.
76.
[reaction: see text] Diastereoselective reductive coupling reactions of omega-vinyl tethered cyclic imides are achieved by a preexisting stereocenter at an allylic position. Particularly noteworthy is the effective use of a 1:2 mixture of Ti(O-i-Pr)4 and n-BuLi to afford the N-acylhemiaminal products in good yields. 相似文献
77.
Systematic investigations of the electronic structures of MO9-6 (M = Ti-Ni) clusters, as in the LaMO3 type perovskite oxides, have been carried out by employing the multiple-scattering Xα (MSXα) method. The crystal-field splitting of the metal d level is found to increase, while the oxygen-to-metal charge-transfer energy decreases across the transition metal series. Systematic trends are also seen in the mixing (covalency) between the metal d and the oxygen 2p orbitals in the series. 相似文献
78.
Santra S Dogra SK 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2000,56(5):915-925
The absorption and fluorescence spectra of 2-(2'-aminophenyl)benzimidazole (2-APBI) have been studied in anionic (sodium dodecylsulphate, SDS), cationic (cetyltrimethylammonium bromide, CTAB) and non-ionic micelles (Tween-80, TritonX-100) at different acid-base concentrations. Spectral characteristics of 2-APBI at various acid concentrations have established only one kind of monocation (MC) in Tween-80 and TritonX-100 (TX-100), whereas two kinds of MCs are present in SDS. Above study has further shown that there is a strong hydrogen bonding interaction between the polar polyoxyethylene groups of non-ionic micelles and the MCs of 2-APBI. This interaction is responsible for the stabilization of the MC III to MC III' which is more planar than either MC II or MC III, which is otherwise less stable in water. This is substantiated by the lifetime data, fluorescence excitation spectra and the pKa values of the monocation-neutral (MC-N) equilibrium. 相似文献
79.
Six clusters Ag(8)(micro(8)-X)[Se(2)P(OR)(2)](6)(PF(6)) (R = Et, X = Cl, 1a, X = Br, 1b; R = Pr, X = Cl, 2a, X = Br, 2b; R = (i)Pr, X = Cl, 3a, X = Br, 3b) were isolated from the reaction of [Ag(CH(3)CN)(4)](PF(6)), NH(4)[Se(2)P(OR)(2)], and Bu(4)NX in a molar ratio of 4:3:1 in CH(2)X(2). Positive FAB mass spectra show m/z peaks at 2573.2 for 1a, 2617.3 for 1b, 2740.9 for 2a, 2786.9 for 2b, 2742.3 for 3a, and 2787.0 for 3b due to respective molecular cation, (M - PF(6))(+). (31)P NMR spectra of 1a-3b display a singlet at delta 82.3, 81.5, 82.9, 81.7, 76.3, and 75.8 ppm with a set of satellites (J(PSe) = 661, 664, 652, 652, 656, and 656 Hz, respectively). The X-ray structure (1a-2b) consists of a discrete cationic cluster in which eight silver ions are linked by six diselenophosphate ligands and a central micro(8)-Cl or micro(8)-Br ion with a noncoordinating PF(6)(-) anion. The shape of the molecule is a halide-centered distorted Ag(8) cubic cluster. The dsep ligand exhibits a tetrametallic tetraconnective (micro(2), micro(2)) coordination pattern, and each caps on a square face of the cube. Each silver atom of the cube is coordinated by three selenium atoms and the central chloride or bromide ion. Additionally, molecular orbital calculations at the B3LYP level of the density functional theory have been carried out to study the Ag-micro(8)-X (X = Cl, Br) interactions for cluster cations [Ag(8)(micro(8)-X)[Se(2)P(OR)(2)](6)](+). Calculations show very weak bonding interactions exist between micro(8)-X and Ag atoms of the cube. 相似文献
80.
Scheit S Averbukh V Meyer HD Moiseyev N Santra R Sommerfeld T Zobeley J Cederbaum LS 《The Journal of chemical physics》2004,121(17):8393-8398
The interatomic Coulombic decay (ICD) in the Ne dimer is discussed in view of the recent experimental results. The ICD electron spectrum and the kinetic energy release of the Ne+ fragments resulting after Coulomb explosion of Ne2 (2+) are computed and compared to the measured ones. A very good agreement is found, confirming the dynamics predicted for this decay mechanism. The effect of the temperature on the electron spectrum is briefly investigated. 相似文献