全文获取类型
收费全文 | 88篇 |
免费 | 1篇 |
专业分类
化学 | 45篇 |
力学 | 1篇 |
数学 | 11篇 |
物理学 | 32篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 4篇 |
2012年 | 3篇 |
2011年 | 2篇 |
2010年 | 1篇 |
2009年 | 8篇 |
2008年 | 3篇 |
2007年 | 9篇 |
2006年 | 8篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1996年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有89条查询结果,搜索用时 15 毫秒
61.
Bakharev ON Abu-Shiekah IM Brom HB Nugroho AA McCulloch IP Zaanen J 《Physical review letters》2004,93(3):037002
By Cu NMR we studied the spin and charge structure in Nd(2-x)Ce(x)CuO(4-delta). For x=0.15, starting from a superconducting sample, the low temperature magnetic order in the sample reoxygenated under 1 bar oxygen at 900 degrees C reveals a peculiar modulation of the internal field, indicative of a phase characterized by large charge droplets ("blob" phase). By prolonged reoxygenation at 4 bars the blobs break up and the spin structure changes to that of an ordered antiferromagnet. We conclude that the superconductivity in the n-type systems competes with a genuine type I Mott-insulating state. 相似文献
62.
63.
A zwitter-ionic salt 2-piperidinyl-4-dinitromethyl-1,3,5-triazin(1H,5H)-6-one is studied by the single crystal X-ray analysis. The crystals are monoclinic: a = 11.526(1) Å, b = 9.211(1) Å, c = 12.182(1) Å; β = 110.69(1)°, V = 1209.9(2) Å3, space group P21/n; Z = 4, ρcalc = 1.560 g/cm3. The transformation of the dinitromethyl fragment conformation, the conjugation of one of nitrogroups with the 1,3,5-triazine ring, and an intramolecular hydrogen bond are revealed. The 1,3,5-triazine cycle is strongly distorted due to lactam-lactim tautomerism. 相似文献
64.
Shilina M. I. Bakharev R. V. Kuramshina G. M. Smirnov V. V. 《Russian Chemical Bulletin》2004,53(2):297-305
Products of co-condensation of aluminum chloride and cobalt(ii) chloride vapors were studied by low-temperature (80—200 K) IR spectroscopy. In addition to 2 : 1 complexes, previously unknown equimolar associates were found and their IR spectra were investigated. Quantum-mechanical calculations were carried out including electron correlation with the use of the B3LYP and PBE density functionals. The geometric structures were optimized and harmonic vibrational frequencies of the molecules of aluminum chloride, cobalt chloride, and their complexes with different compositions were calculated. Under conditions of limited molecular mobility, the (AlCl3)2·CoCl2 complexes can be stabilized in structures containing the Co atom in a tetrahedral or distorted octahedral environment. Their thermal stability limits were determined. It was found that labile ionic species are generated in the reactions of aluminum chloride complexes with cobalt chloride with different compositions at 120—170 K. 相似文献
65.
Physics of the Solid State - Abstract—Features of focusing spin waves in ferromagnets with magnetic moment exchange interaction with the closest neighbors and second neighbors are explored.... 相似文献
66.
67.
Kyrill Yu. Suponitsky Ivan V. Fedyanin Valentina A. Karnoukhova Vladimir A. Zalomlenkov Alexander A. Gidaspov Vladimir V. Bakharev Aleksei B. Sheremetev 《Molecules (Basel, Switzerland)》2021,26(24)
Co-crystallization is an elegant technique to tune the physical properties of crystalline solids. In the field of energetic materials, co-crystallization is currently playing an important role in the engineering of crystals with improved performance. Here, based on an analysis of the structural features of the green primary explosive, tetramethylammonium salt of 7-oxo-5-(trinitromethyl)-4,5,6,7-tetrahydrotetrazolo[1,5-a][1,3,5]triazin-5-ide (1), a co-former such as the powerful secondary explosive, benzotrifuroxan (BTF, 2), has been proposed to improve it. Compared to the original 1, its co-crystal with BTF has a higher detonation pressure and velocity, as well as an initiating ability, while the impact sensitivity and thermal stability remained at about the same level. Both co-formers, 1 and 2, and co-crystal 3 were characterized by single-crystal X-ray diffraction and their crystal packing was analyzed in detail by the set of approaches, including periodic calculations. In the co-crystal 3, all intermolecular interactions were significantly redistributed. However, no new types of intermolecular interactions were formed during co-crystallization. Moreover, the interaction energies of structural units in crystals before and after co-crystallization were approximately the same. A similar trend was observed for the volumes occupied by structural units and their densifications. The similar nature of the organization of the crystals of the co-formers and the co-crystal gives grounds to assert that the selected co-formers are an ideal pair for co-crystallization, and the invariability of the organization of the crystals was probably responsible for the preservation of some of their properties. 相似文献
68.
Bulanin V. V. Bakharev N. N. Gusev V. K. Kurskiev G. S. Minaev V. B. Patrov M. I. Petrov A. V. Petrov Yu. V. Sakharov N. V. Shchegolev P. B. Telnova A. Yu. Tolstyakov S. Yu. Yashin A. Yu. 《Physics of Atomic Nuclei》2020,83(7):1124-1130
Physics of Atomic Nuclei - The Alfvén oscillations were studied using the multifrequency Doppler backscattering (DBS) method on the Globus-M spherical tokamak during the neutral deuterium... 相似文献
69.
N. N. Bakharev F. V. Chernyshev V. I. Davydenko P. R. Goncharov V. K. Gusev G. S. Kurskiev A. D. Melnik V. B. Minaev M. I. Mironov M. I. Patrov Yu. V. Petrov N. V. Sakharov P. B. Shchegolev A. D. Sladkomedova A. Yu. Telnova S. Yu. Tolstyakov G. V. Zadvitskiy 《Technical Physics》2017,62(12):1812-1816
A high-energy counter-NBI has been applied for the first time on the Globus-M spherical tokamak. An ELM-free H-mode has been obtained. However, no significant increase in the ion temperature and plasma energy content compared to ELMy H-mode has been observed. This is due to a high level of the fastion losses. Neither increase in the plasma current nor an increase in plasma-wall distance resulted in an increase in NB heating efficiency as it occurred during the co-NBI experiments. 相似文献
70.
I. I. Kuleyev I. G. Kuleyev S. M. Bakharev A. V. Inyushkin 《Physics of the Solid State》2013,55(7):1545-1556
The effect of dispersion on the focusing of thermal phonons and on the thermal conductivity of silicon single crystals in the boundary scattering regime has been investigated. Analysis of the spectra of acoustic modes obtained for silicon single crystals from inelastic neutron scattering data has demonstrated that, upon transition from long-wavelength phonons to short-wavelength phonons, the directions of their focusing change. With an increase in temperature, this leads to a change in the anisotropy of thermal conductivity of phonons with different polarizations and, consequently, to a change in the anisotropy of the total thermal conductivity. Analysis of the temperature dependence of the thermal conductivity has revealed that the presence of extended flattened sections in the spectrum of short-wavelength transverse phonons indicates anomalously low values of the group velocity and, accordingly, a significant decrease in the contribution from these phonons to the thermal conductivity with increasing temperature. The contribution from longitudinal phonons to the thermal conductivity also significantly increases even at temperatures higher than 110 K and becomes dominant. 相似文献