全文获取类型
收费全文 | 49篇 |
免费 | 0篇 |
专业分类
化学 | 24篇 |
数学 | 2篇 |
物理学 | 23篇 |
出版年
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2014年 | 1篇 |
2013年 | 1篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2010年 | 2篇 |
2009年 | 1篇 |
2008年 | 3篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2003年 | 1篇 |
2001年 | 3篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1980年 | 1篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有49条查询结果,搜索用时 250 毫秒
11.
A. A. Sorokin G. K. Ryasny B. A. Komissarova L. N. Fomicheva A. V. Tsvyashchenko S. M. Nikitin 《Hyperfine Interactions》2006,171(1-3):269-275
The perturbed angular correlation (PAC) measurements with the 111In-111Cd nuclear probe embedded into the lattice of the cubic (C15) Laves compound ZrZn2 showed that 111Cd nuclei experienced an axially symmetric electric quadrupole interaction with a frequency ν
Q
= 132.4 MHz at room temperature. The samples were synthesized and doped with the probe at a pressure 8 GPa. The temperature
dependence of ν
Q
was shown to be linear: ν
Q
(T) = 147(1 − 0.033 T) MHz. Since the value of ν
Q
is very close to that known for 111Cd in the lattice of Zn, we have checked if it could be assigned to residual Zn metal in the sample. For the Zn sample melted
and doped with 111In at 8 GPa we have obtained ν
Q
= 117.3 MHz at 300 K and 127 MHz at 80 K – both values considerably lower than that for 111In doped Zn samples prepared at an ambient pressure. These data, and the fact that ν
Q
(T) in Zn is known to follow the T
3/2 law, allow to attribute the ν
Q
value quoted above to 111Cd nuclei at the substitutional sites with tetrahedral symmetry in the Zn sublattice of ZrZn2. 相似文献
12.
Nikolskaya E. D. Zhunina O. A. Yabbarov N. G. Zenin V. A. Tereshchenko O. G. Fomicheva M. V. Sokol M. B. Lobanov A. V. Severin E. S. 《Russian Chemical Bulletin》2017,66(12):2348-2348
Russian Chemical Bulletin - To the article “Antitumor activity of carboplatin in the composition of a copolymer of lactic and glycolic acids,” by E. D. Nikolskaya, O. A. Zhunina, N. G.... 相似文献
13.
Leont'ev A. V. Mironov O. A. Fomicheva O. A. Proskurnina M. V. Zefirov N. S. 《Russian Journal of General Chemistry》2001,71(6):905-906
Reaction of nitrogen(I) oxide with nitrogen-fixing systems Li/Me3SiCl/MCl
n
(MCl
4n
= CrCl3, CoCl2, Cp2TiCl2, FeCl3, CuCl2). In these systems nitrogen(I) oxide, molecular nitrogen, and air nitrogen undergo reductive silylation to tris(trimethylsilyl)amine. The efficiency of the process was estimated by the molar ratio of the tris(trimethylsilyl)amine formed to metal chloride MCl
n
n. The reaction of N2O with the nitrogen-fixing systems including CoCl2 and Cp2TiCl2 is not exhausted by the reduction of the former to molecular nitrogen and its subsequent fixation by transition metal complexes. 相似文献
14.
Leont'ev A. V. Fomicheva O. A. Proskurnina M. V. Zefirov N. S. 《Russian Journal of Organic Chemistry》2001,37(4):496-498
The reaction of nitrous oxide with some cyclopentadienyl compounds of cobalt, rhodium, and titanium was studied. The corresponding furans were obtained in low to moderate yields. 相似文献
15.
16.
L. S. Khaikin O. E. Grikina B. I. Zhilinskii E. A. Zhilinskaya E. G. Baskir R. V. Nepomnyashchii O. A. Fomicheva M. V. Proskurnina 《Russian Chemical Bulletin》1998,47(9):1653-1665
The equilibrium geometric parameters and structures of transition states of internal rotation for the molecules of methyldicyanophospine
MeP(CN)2 and its isocyano analog MeP(NC)2 were calculated by the RHF and MP2 methods with the 6–31G* and 6–31G** basis sets. At the MP2 level, the total energy of cyanide is −35 kcal mol−1 lower than that of isocyanide and the barriers to internal rotation of methyl group for MeP(CN)2 and MeP(NC)2 are 2.2 and 2.7 kcal mol−1, respectively. For both molecules, the one-dimensionalab initio potential functions of internal rotation approximated by a truncated Fourier series were used to determine the frequencies
of torsional transitions by solving direct vibrational problems for a non-rigid model. The Raman spectrum of crystalline MeP(CN)2 was recorded in the range 3500–50 cm−1. The vibrational spectra of this compound were interpreted by scalingab initio force fields calculated by the RHF and MP2 method. The vibrational spectrum of methyldiisocyanophosphine was predicted with
the use of the obtained scale factors.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1703–1714, September, 1998. 相似文献
17.
V. K. Yu K. D. Praliev E. E. Fomicheva R. D. Mukhasheva S. G. Klepikova 《Chemistry of Heterocyclic Compounds》2006,42(4):512-519
New 7-alkoxyalkyl-3-thia-7-azabicyclo[3.3.1]nonan-9-ones were synthesized by the double Mannich cyclization of tetrahydrothiopyran-4-one
with suitable alkoxyalkylamines and paraformaldehyde in acetous methanol. Wolff-Kishner decarbonylation of these bicyclic
ketones gave 7-alkoxyalkyl-3-thia-7-azabicyclo[3.3.1]nonanes. The reduction of 7-alkoxyalkyl-3-thia-7-azabicyclo[3.3.1]nonan-9-ones
by alkali metal hydride complexes leads to a mixture of two stereoisomeric secondary alcohols, which are epimers at C(9). Active analgesic, antiarrhythmic, and antibacterial compounds were found among these products.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 585–592, April, 2006. 相似文献
18.
19.
A marked decrease in reactivity has been shown for oxaadamantane towards bromination and oxidation when compared with adamantane. The mono- and dihydroxy and acetoxy substituents in the products occupied positions in the molecule remote from the oxa bridge.M. V. Lomonosov State University, Moscow 119899. Translated from Khimiya Geterotsiklicheskikh Soedineii, No, 5, pp. 608–612, May, 1994. Original article submitted April 26, 1994. 相似文献
20.
A.V. Tsvyashchenko L.N. Fomicheva O.I. Kochetov A. Velichkov M. Budzynski G.K. Ryasny 《Solid State Communications》2007,142(11):664-669
The time-differential perturbed angular correlations technique (TDPAC) has been employed for measuring the parameters of hyperfine interactions in earlier known RAl3 compounds, synthesized at high pressure (8 GPa) and high temperature, where R = La, Ce, Sm, Gd, Tb, Dy, Ho, Er, Yb and Lu. The 111Cd(111In) radioactive atom was used as a probe nucleus. The X-ray method has revealed that with the increase in the atomic number of a rare-earth element R, the obtained RAl3 high-pressure phases crystallize, respectively, into orthorhombic, hexagonal and cubic structures. It has been found that in the compounds containing R=La, Ce, Sm and Gd, a deviation from earlier known structural types and the formation of new ones is observed, which is associated with the change of the stoichiometric composition of the said compounds. The results of the PAC measurements have confirmed the deviation from the predetermined stoichiometric composition 1R:3Al for the compounds LaAl3, CeAl3, SmAl3 and GdAl3 and have verified the RAl3 stoichiometric structure for the other high-pressure phases obtained in this work. 相似文献