全文获取类型
收费全文 | 180篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
化学 | 87篇 |
晶体学 | 3篇 |
力学 | 3篇 |
数学 | 25篇 |
物理学 | 65篇 |
出版年
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 7篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 2篇 |
2012年 | 4篇 |
2011年 | 6篇 |
2010年 | 4篇 |
2009年 | 7篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2002年 | 10篇 |
2001年 | 8篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 1篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1981年 | 2篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 4篇 |
1970年 | 5篇 |
1969年 | 3篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1957年 | 1篇 |
排序方式: 共有183条查询结果,搜索用时 343 毫秒
101.
V. G. Sevast’yanov P. Ya. Nosatenko V. V. Gorskii Yu. S. Ezhov D. V. Sevast’yanov E. P. Simonenko N. T. Kuznetsov 《Russian Journal of Inorganic Chemistry》2010,55(13):2073-2088
Reference books and original studies devoted to the determination of the saturation vapor pressure of silicon in a wide range
of temperatures have been analyzed. It has been established that no reliable experimental data in the range of high temperatures
(above 2000 K) are available in the literature. It has been demonstrated that there is a need to perform additional theoretical
and experimental investigations with the use of different methods. The total pressure and partial pressures of Si
n
(n = 1−6) molecules over liquid silicon are calculated in the temperature range 1700–3400 K. The calculation of the composition
of the gas phase over the “Si(l)-container” systems is performed. Materials of the crucibles intended for the use in experimental
investigations of the temperature dependence of the saturation vapor pressure of silicon over the liquid phase are recommended. 相似文献
102.
P. A. Perminov I. O. Dzhun A. A. Ezhov S. V. Zabotnov L. A. Golovan’ V. I. Panov P. K. Kashkarov 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(1):93-95
The possibility to produce silicon nanoparticles by the method of the pulse laser ablation of monocrystaline silicon targets
in the water, glycerol and liquid nitrogen have been shown. Studies by the atomic-force microscopy and Raman scattering methods
revealed the nanoparticles have a crystalline structure and their mean size depends on the buffer liquid composition. 相似文献
103.
L. V. Skripnikov A. N. Petrov N. S. Mosyagin V. F. Ezhov A. V. Titov 《Optics and Spectroscopy》2009,106(6):790-792
The potential curves of the ground states of the TlF molecule and TlF? anion are ab initio calculated by the relativistic coupled clusters method using a generalized relativistic pseudopotential. The corresponding spectroscopic parameters are calculated and it is shown that TlF? is stable in the lowest vibrational states. The information obtained is necessary for preparing a new series of experiments aimed at searching for CP-noninvariant effects in nucleon-nucleon interactions on the basis of the TlF molecule. 相似文献
104.
Babenko DI Ezhov AA Turygin DS Ivanov VA Ivanov VK Arslanov VV Kalinina MA 《Langmuir : the ACS journal of surfaces and colloids》2012,28(1):125-133
We describe a new type of colloidal 2D gels formed in mixed Langmuir monolayers of stearic acid and octadecylamine on a surface of gold hydrosol. The adsorption of gold nanoparticles on the mixed monolayer led to an increase of interactions between oppositely charged surfactants giving a "soap" of mixed fatty salt. The observed effect is equivalent to a virtual "cooling" of floating monolayer, which undergoes rapid condensation on a surface of aqueous colloid. The consequent shrinking and rearrangement of the monolayer resulted in aggregation of nanoparticles into colloidal 2D "soap"-gels, which represented arrested colloidal phases within nonadsorbing organic medium. When sequentially deposited onto solids by Langmuir-Blodgett technique, the 2D "soap"-gels separated into organic and colloidal phases and gave dendrite-like bilateral organic crystallites coated with gold nanoparticles. The reported colloidal "soap"-assembly can offer a new opportunity to design 2D colloidal systems of widely variable chemistry and structures. 相似文献
105.
M.K. Islam S. Biswas N.A. Chowdhury A. Mannan M. Salahuddin AA Mamun 《等离子体物理论文集》2022,62(1):e202100073
A theoretical investigation has been carried out on the propagation of non-linear ion-acoustic shock waves (IASHWs) in a magnetized degenerate quantum plasma system composed of inertial non-relativistic positively charged light and heavy ions, inertialess non-relativistically or ultra-relativistically degenerate electrons and positrons. The reductive perturbation method has been employed to derive the Burgers' equation. It has been observed that under consideration, our plasma model supports only positive potential shock structure. It is also found that the amplitude and steepness of the IASHWs have been significantly modified by the variation of ion kinematic viscosity, oblique angle, number density, and charge state of the plasma species. The results of our present investigation will be helpful for understanding the propagation of IASHWs in white dwarfs and neutron stars. 相似文献
106.
Commensurability between inter-vortex distance and crystal lattice constant is investigated by angular dependent magnetization
in very pure twinned and twin-free NdBa2 Cu3 Oy single crystals. With increasing temperature the incommensurate states split up and become finally commensurate with half
the vortex distance. These new commensurate states are related to a substructure of the intrinsic pinning potential within
the unit cell and discussed with respect to temperature, field, anisotropy, and twin structure. 相似文献
107.
MJ Lazaro AA Herod M Domin Y Zhuo CA Islas R Kandiyoti 《Rapid communications in mass spectrometry : RCM》1999,13(14):1401-1412
Three methods for determining a 'safe' estimate for high-mass limits of MALDI spectra of coal derived liquids were explored, using a sample of coal-tar pitch and its pyridine-insoluble fraction. Co-addition of increasing numbers of single-shot spectra (10, 30, 50 and 100 pulses) showed visually observable reductions in noise levels, consistent with robust and statistically meaningful signals. Three separate types of post-acquisition calculation were used to identify high-mass limits of the spectra. (i) A literature method indicated high-mass limits similar to those observed visually-as a shift from baseline at the highest masses, nearly 350 000 u for the coal tar pitch and about 390 000 u for its pyridine insoluble fraction. (ii) Comparing instrument signal with pre-selected multiples of the standard deviation, upper mass estimates of between 40-60 000 u for the coal-tar pitch and about 95 000 u for its pyridine-insoluble fraction were found. (iii) Calculation of the slope was used to identify 'lift-off' of the spectrum from baseline. The angle between the smoothed spectrum and the baseline was matched to a pre-selected value (e.g. 0.5 degrees and 1 degrees ). However, the arbitrary specification of the key parameter did not establish this last method on a firm basis. The choice of a criterion for estimating high-mass limits of MALDI spectra remains a semi-quantitative procedure; a reasonably conservative high-mass limit may be estimated by comparison of signal with five times the standard deviation. However, evaluation of size exclusion chromatograms of the present samples using polystyrene standards suggests that molecular mass distributions of pitch samples arrived at by MALDI mass spectrometry are, at least partly, determined by the limitations of available instruments. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
108.
Nikolaev N. A. Mamrashev A. A. Andreev Yu. M. Ezhov D. M. Lanskii G. V. Lubenko D. M. Kinyaevskii I. O. Solntsev V. P. 《Russian Physics Journal》2021,63(12):2066-2069
Russian Physics Journal - Spectral dependences of components of the refractive index and absorption coefficient in a Li2B4O7 (LB4) nonlinear crystal are determined in the THz range for the first... 相似文献
109.
E. P. Simonenko N. P. Simonenko Yu. S. Ezhov V. G. Sevastyanov N. T. Kuznetsov 《Physics of Atomic Nuclei》2015,78(12):1357-1365
The synthesis conditions of refractory tantalum–zirconium carbide Ta0.8Zr0.2C on the basis of Ta2O5–ZrO2–C ultrafine initial blend prepared via the sol–gel method are explored. The initial blend is prepared via hydrolysis in the presence of Ta(OC5H11)5 and [Zr(O2C5H7)4–x (OC5H11) x ] carbon source polymer solutions, gel drying, and carbonization at a temperature of 450°C. A series of the carbothermal synthesis experiments is implemented at various temperatures and exposure times. The synthesis conditions are shown to affect not only the phase composition of products but also their oxidation resistance related to the particle size. 相似文献
110.
Yu. S. Ezhov S. A. Komarov E. P. Simonenko R. G. Pavelko V. G. Sevast’yanov N. T. Kuznetsov 《Journal of Structural Chemistry》2009,50(1):153-157
Methods of quantum chemistry and gas phase electron diffraction (at a temperature of 303±5 K) are applied to determine parameters of the geometric configuration of C(SiCl3)4 tetrakis(trichlorosilyl)methane. Frequencies of the vibrational spectrum are calculated. The value of the internal rotation barrier of SiCl3 groups relative to the Si-C bond is 148.7 kJ/mol. 相似文献