全文获取类型
收费全文 | 43篇 |
免费 | 3篇 |
国内免费 | 1篇 |
专业分类
化学 | 13篇 |
晶体学 | 1篇 |
数学 | 7篇 |
物理学 | 26篇 |
出版年
2017年 | 1篇 |
2014年 | 4篇 |
2013年 | 1篇 |
2012年 | 3篇 |
2011年 | 1篇 |
2004年 | 1篇 |
2001年 | 1篇 |
1994年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有47条查询结果,搜索用时 15 毫秒
1.
2.
Hongyuan Yan Mengmeng Gao Chen Yang Mande Qiu 《Analytical and bioanalytical chemistry》2014,406(11):2669-2677
Ionic liquid-modified magnetic polymeric microspheres (ILMPM) were prepared based on Fe3O4 magnetic nanoparticles (MNPs) and ionic liquids (ILs) incorporated into a polymer. The composites were characterized using scanning electron microscopy, Fourier transform infrared analysis, thermogravimetric analysis, X-ray diffraction, and vibrating magnetometer, which indicated that ILMPM had a regularly spherical shape and strong magnetic property. The obtained ILMPM were successfully applied as a special adsorbent of magnetic dispersive solid phase extraction (MDSPE) for the rapid extraction and isolation of sulfamonomethoxine sodium and sulfachloropyrazine sodium in urine. The factors that affected extraction efficiency, such as adsorption conditions, desorption conditions, washing and elution solvents, and pH of the sample solution, were optimized. Under the optimum condition, good linearity in the range of 0.005–2.0 μg g?1 (r?≥?0.9996) was obtained for the two sulfonamides (SAs); the average recoveries at three spiked levels ranged from 86.9 to 102.1 %, with relative standard deviations of ≤4.3 %. The presented ILMPM-MDSPE method combined the advantages of ILs, MNPs, and MDSPE and therefore could be potentially applied for rapid screening of SAs in urine. 相似文献
3.
The K absorption spectra of nickel and selenium have been recorded photographically in the pure metals and the compounds NiSe and NiSe2. It has been observed that the Ni discontinuity shifts toward the high energy side with respect to that in the pure metal by about 5.0 eV for NiSe and about 6.7 eV for NiSe2. The Se edge in both these compounds is found to shift by about 2.6 eV toward the low energy side with respect to that in pure selenium. From these results it is possible to obtain the bonding pictures for the compounds. The compound NiSe appears to have resonating p3 type of bonding. For NiSe2 the orbitals involved in the bonding are d2sp3 for the metal atom and sp3 for the metalloid atom. The electrical behaviour of the compounds has been explained on the basis of these bonding pictures. 相似文献
4.
For most of the transitions of theK andL series x-ray spectra the ratio of the contributions of the competing multipoles, δ2, is independent of the radial matrix element in the non-relativistic limit. In the present paper calculations of δ2 are made in the non-relativistic limit which give the relative strengths of the two closely competing electric and magnetic multipoles. The dominant mode in the emission processes of the transitions in theK andL series x-ray spectra has been assigned on the basis of these calculations. 相似文献
5.
6.
Chintamani Mande Subha Chattopadhyay Prabodh C Deshmukh R Padma Pranawa C Deshmukh 《Pramana》1990,35(4):397-403
A new scale of electronegativity based on X-ray spectroscopic data was earlier presented by Mande and others for the elements3Li to54Xe. The present paper reports an extension of this scale carried out for most of the heavier elements lying between55Cs and92U. The present approach is based on the physical interpretation of electronegativity of an atom as the attractive electrostatic
force it exerts at a distance equal to its covalent radius. To estimate this force, experimental spectroscopic data have been
employed. The merits of such an approach have been pointed out recently by Mullay and may be of interest in the context of
the intimate relation found between electronegativity and superconducting transition temperature. 相似文献
7.
Chintamani Mande A. V. Pendharkar M. C. Chakravorti 《Proceedings Mathematical Sciences》1972,75(5):209-216
The X-ray LIII absorption edge of rhenium in the pure metal and in two compounds, namely, K2ReCl6 and KReO4 has been studied using a Cauchois type bent crystal spectrograph of 40 cm diameter. The splitting of the main absorption discontinuity has been observed for the first time in the compounds. This splitting and the edge structure of the Re LIII discontinuity in the compounds have been interpreted on the basis of molecular orbital diagrams. The crystal field splitting, Δ, has been determined experimentally in both the compounds in the solid state. 相似文献
8.
9.
X-ray absorption study of two intermetallic compounds MnSe2 and CoSe2 has been carried out using a Cauchois type bent crystal spectrograph. The metal K absorption edges in both the compounds are found to shift toward the high energy side with respect to the discontinuities in the pure metals. On the other hand, the Se K absorption edge in both these compounds is found to shift toward the lower energies. Emission study of the compound MnSe2 has shown that the Mn Kβ 5 band in this compound is shifted toward the high energy side with respect to that in the pure metal. From the magnetic data and the results obtained in this work it is possible to obtain the chemical bonding pictures in these compounds. For MnSe2 the bondings sp 3 d 2 for the metal atom andsp 3 for the metalloid atom have been suggested. For CoSe2 the bondings appear to bed 2 sp 3 for the metal atom andsp 3 for the metalloid atom. These bondings are compatible with the pyrite type structure of these compounds. It is possible to explain the electrical behaviour of the compounds on the basis of these bonding pictures. 相似文献
10.