全文获取类型
收费全文 | 102篇 |
免费 | 1篇 |
专业分类
化学 | 8篇 |
晶体学 | 6篇 |
数学 | 48篇 |
物理学 | 41篇 |
出版年
2022年 | 3篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 9篇 |
2017年 | 10篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 3篇 |
2013年 | 10篇 |
2012年 | 4篇 |
2011年 | 6篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 6篇 |
2007年 | 6篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2003年 | 1篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1990年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有103条查询结果,搜索用时 15 毫秒
1.
A. G. Kulikov A. E. Blagov N. V. Marchenkov V. A. Lomonov A. V. Vinogradov Yu. V. Pisarevsky M. V. Kovalchuk 《JETP Letters》2018,107(10):646-650
The process of formation of surface structures in a paratellurite crystal (α-TeO2) in an external electric field has been studied by in situ X-ray diffraction (XRD) measurements. This process is reversible and its dynamics (duration of tens of minutes) corresponds to the formation of a screening layer near the insulator–metal interface owing to the counter migration of oxygen ions and vacancies in the external electric field. The formation of domains has been observed in the experiment as the broadening and splitting of the XRD curve and is explained by mechanical stresses that appear in the high electric field near the surface in view of the piezoelectric effect and are responsible for a ferroelectric α–β phase transition. A change in the lattice parameter near the anode (surface of the crystal with a positive external charge) has been detected simultaneously. This change is due to the local rearrangement of the crystal structure because of the inflow of oxygen ions in this region and outflow of oxygen vacancies. 相似文献
2.
N. I. Kourov V. V. Marchenkov A. V. Korolev A. V. Lukoyanov 《Physics of the Solid State》2016,58(7):1500-1504
The heat capacity of band magnets Fe2MeAl (Me = Ti, V, Cr, Mn, Fe, Co, Ni) ordered in crystal structure L21 has been measured in the range 2 K ≤ T ≤ 50 K. The dependences of the Debye temperature ΘD, the Sommerfeld coefficient γ, and the temperature-independent contribution to heat capacity C0 on the number of valence electrons z in the alloys have been determined. 相似文献
3.
N. I. Kourov Yu. A. Perevozchikova H. W. Weber V. V. Marchenkov 《Physics of the Solid State》2016,58(7):1355-1360
The transport properties of half-metallic ferromagnetic Heusler alloys Co2MeAl (Me = Ti, V, Cr, Mn, Fe are transition 3d metals) have been measured in the temperature range of 4–900 K. The specific features of the behavior of the resistivity have been considered in the framework of the two-current model of conductivity that takes into account the existence of the energy gap in the electronic spectra of the alloys near the Fermi level of one of electron subbands that differs in the spin direction. 相似文献
4.
I. I. Atknin N. V. Marchenkov A. G. Kulikov A. E. Blagov M. V. Kovalchuk 《Journal of Experimental and Theoretical Physics》2020,130(1):7-13
An approach to the simulation of reciprocal space maps corresponding to the maps obtained experimentally by the triple crystal X-ray diffractometry (TXD) is proposed. A specific feature of the approach is the use of spectral angular distribution diagrams of X-ray radiation, which allows one to visualize the two-dimensional pattern of the spectral angular “composition” of an X-ray beam after its interaction with each element of the scheme and thus to take into account the contribution of the hardware function of the experimental setup. The algorithms developed allow calculations for a wide class of radiation sources (from an X‑ray tube with any material of the anode to a synchrotron radiation source) and X-ray optical elements (slits, X-ray mirrors of monochromators, and analyzers). The results of simulation are compared with the experimental data for dispersive diffraction geometry, which confirms the adequacy of the proposed approach and its applicability to the simulation of a diffraction pattern corresponding to a real experiment in the triple crystal scheme. 相似文献
5.
6.
E. B. Aleksandrov M. V. Balabas S. P. Dmitriev N. A. Dovator A. I. Ivanov I. A. Krasnoshchekova V. N. Kulyasov V. V. Marchenkov A. S. Pazgalev A. P. Serebrov V. A. Soloveĭ G. E. Shmelev 《Technical Physics》2007,52(3):389-391
Experiments aimed to determine the sensitivity and the optical shift of the output frequency of a magnetometer based on optical pumping of cesium atoms and intended for a neutron magnetic resonance stabilization system are described. A gradiometric arrangement used in these experiments makes it possible to reduce the effect of magnetic field variations on measurements. 相似文献
7.
8.
The method for the simulation of various cases of collisions between spherical solid particles in suspensions or emulsions
(for example, in mixtures of polymers) moving in convergent flows is proposed. These flows arise in many technological schemes
for the processing of polymers. The derived formulas make it possible to relate interparticle distances with the dimensions
of particles and their volume fraction. The effect of the distribution of particles with respect to their dimensions and distances
between them is considered. The flow lines are proposed to be described by two functions: (i) a parabolic dependence for a
reservoir and (ii) a logarithmic dependence at a capillary inlet. The height of the conjugation of the above dependences appears
to be similar for both flow lines. Under similar conditions, the number of collisions between particles and their rate dramatically
increase after passage from a reservoir to a capillary as well as with a decrease in the radius of the particles (at a constant
volume fraction). The experiment on microimaging of the frozen emulsion of PMMA in PS at different regions of convergent flow
shows a fair qualitative correlation between experimental and calculated data. 相似文献
9.
N. I. Kourov V. G. Pushin A. V. Korolev V. V. Marchenkov E. B. Marchenkova V. A. Kazantsev H. W. Weber 《Physics of the Solid State》2011,53(1):91-99
The effect of one-percent substitution of iron for manganese on the physical (magnetic, electrical, thermal, and galvanomagnetic)
properties and the crystal structure of the Ni54Mn21Ga25 alloy has been investigated. It has been demonstrated that the deviation of the alloy composition from the stoichiometric
composition Ni50Mn25Ga25 leads to the formation of a mixed ferromagnetic-antiferromagnetic state. The atomic disordering and nanostructuring of the
alloys under investigation due to the severe plastic deformation by torsion in Bridgman anvils to sizes of 10–20 nm result
in the suppression of reversible magnetically controlled shape memory effects. 相似文献
10.
Trubetskaya OE Shaloiko LA Demin DV Marchenkov VV Proskuryakov II Coelho C Trubetskoj OA 《Analytica chimica acta》2011,(2):263-268
Polyacrylamide gel electrophoresis of chernozem soil humic acids (HAs) followed by observation under UV (312 nm) excitation light reveals new low molecular weight (MW) fluorescent fractions. Ultrafiltration of HAs sample in 7 M urea on a membrane of low nominal MW retention (NMWR, 5 kDa) was repetitively used for separation of fluorescent and non-fluorescent species. Thirty ultrafiltrates and the final retentate R were obtained. Fluorescence maxima of separate ultrafiltrates were different and non-monotonously changed in the range of 475–505 nm. Fluorescence maxima of less than 490 nm were detected only in the four first utrafiltrates. For further physical–chemical analyses all utrafiltrates were combined into a fraction called UF < 5 (NMW < 5 kDa). Retentate R demonstrated very weak fluorescence under 270 nm excitation, while fluorescence intensity of UF < 5 was about six times higher than of the bulk HAs. Fraction UF < 5 was further ultrafiltrated on membranes of MNWR 3 kDa and 1 kDa, yielding three subfractions UF3-5, UF1-3 and UF < 1 with NMW 3–5 kDa, 1–3 kDa and <1 kDa, respectively. The validation of the UF procedure was performed by size exclusion chromatography on Sephadex G-25 column. The fluorescence maxima were found to be at 505, 488 and 465 nm for UF3-5, UF1-3 and UF < 1, respectively, with increasing of fluorescence intensity from UF3-5 to UF1-3 to UF < 1 fraction. EPR analysis showed that the amount of free radicals was the largest in retentate R and drastically decreased in fluorescent ultrafiltrates. The results demonstrate that more than one fluorophore is present in chernozem soil HAs complex. 相似文献